System and method for couch sag compensation

ABSTRACT

The method may include obtaining a first set of imaging data affording a sagittal view relating to a subject and a first couch supporting the subject. The first couch may have a plurality of first positions reflected in the first set of imaging data as a first conformation. The method may also include determining a displacement field associated with a first set of imaging data with respect to the reference conformation based on the first conformation and a reference conformation. The method may further include adjusting the first set of imaging data with respect to the reference conformation based on the displacement field. In some embodiments, the method may include obtaining an image of the subject with respect to the reference conformation based on the adjusted first set of imaging data.

CROSS REFERENCE TO RELATED APPLICATIONS

This present application is a continuation of U.S. application Ser. No.17/443,335, filed on Jul. 26, 2021, which is a continuation of U.S.application Ser. No. 16/194,243, filed on Nov. 16, 2018, now patent Ser.No. 11/071,510, which is a continuation of International Application No.PCT/CN2018/075816 filed on Feb. 8, 2018, the entire contents of whichare incorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to a medical system, and moreparticularly, to a system and method for couch sag compensation in amedical or imaging procedure.

BACKGROUND

Various imaging techniques have been widely used in medical diagnosis,radiation therapy planning, surgery planning and other medicalprocedures, such as X-ray imaging, magnetic resonance imaging (MRI),computed tomography (CT), positron emission tomography (PET), etc.Generally, a couch may be used to support and/or transfer a subject tobe examined to a scanning region of an imaging device and/or a treatmentdevice. In some embodiments, a couch loaded with the subject (e.g., apatient) may deform (or referred to as sag or deflect) in a medicalprocedure. For example, in a multi-modality imaging, the couch may sagwhen the couch is extended along the longitudinal direction of the couchto scanning regions of the multi-modality imaging device, causingmismatch of images taken at different positions. As another example, inan imaging guided radiation therapy (IGRT) procedure, the couch may sag,warp, or rotate when the couch is moved from an imaging device to atreatment device, causing inaccurate positioning of a target point(e.g., an anatomical point). Thus, it may be desirable to develop amethod or a system to compensate the sag of a couch.

SUMMARY

According to an aspect of the present disclosure, a method for couch sagcompensation in a medical or imaging procedure is provided. The methodmay include obtaining a first set of imaging data affording a sagittalview relating to a subject and a first couch supporting the subject. Thefirst couch may have a plurality of first positions reflected in thefirst set of imaging data as a first conformation. The method may alsoinclude determining, based on the first conformation and a referenceconformation, a displacement field associated with the first set ofimaging data with respect to the reference conformation. The method mayalso include adjusting, based on the displacement field, the first setof imaging data with respect to the reference conformation. The methodmay also include obtaining, based on the adjusted first set of imagingdata, an image of the subject with respect to the referenceconformation.

In some embodiments, for one first position of the first couch, themethod may further include determining a corrected first point on thereference conformation corresponding to a first point of the first setof imaging data on the first conformation. The first point maycorrespond to the one first position of the first couch. The method mayalso include determining a displacement component associated with thefirst point. A first distance between the corrected first point and anintersection may equal a second distance between the first point and theintersection between the reference conformation and the firstconformation. The displacement component of the first point may bedetermined as a vector from the first point to the corrected firstpoint.

In some embodiments, the displacement component of the first point mayinclude a third distance from the first point to the corrected firstpoint, and a direction from the first point to the corrected firstpoint.

In some embodiments, distances between various first points theintersection may change as a function of corresponding first positionsnonlinearly.

In some embodiments, the method may further include determining adisplacement component of a second point of the first set of imagingdata on the first conformation. The second point may be different fromthe first point. A direction of a vector associated with the secondpoint may be different from the direction of the vector associated withthe first point.

In some embodiments, the method may further include adjusting imagingdata in an axial view corresponding to the first point in the sagittalview based on the displacement component corresponding to the firstpoint.

In some embodiments, the method may further include generating anadjusted 3D image or an adjusted 2D image slice in a view other than theaxial view based on the adjusted imaging data.

In some embodiments, the method may further include moving, based on thedisplacement field, spatial basis function representations correspondingto the first set of imaging data.

In some embodiments, the displacement field may include a plurality ofrotation angles, and the plurality of rotation angles may relate tospatial basis function representations corresponding to the first set ofimaging data.

In some embodiments, at least two rotation angles corresponding todifferent spatial basis function representations may be different.

In some embodiments, the method may further include determining areference position of the first couch reflected in the first set ofimaging data. The first conformation of the first couch may coincidewith the reference conformation at the reference position. The referenceposition may correspond to a reference spatial basis functionrepresentation.

In some embodiments, the rotation angle corresponding to a spatial basisfunction representation may relate to a distance between the spatialbasis function representation and the reference spatial basis functionrepresentation.

In some embodiments, the reference conformation may include a straighthorizontal line.

In some embodiments, the reference conformation may correspond to aplurality of second positions reflected in a second set of imaging data.

In some embodiments, the second set of imaging data may afford asagittal view relating to the subject and a second couch supporting thesubject. The plurality of second positions may correspond to the secondcouch.

According to another aspect of the present disclosure, a method forcouch sag compensation in a medical or imaging procedure is provided.The method may include obtaining a first image slice affording asagittal view relating to a region of interest (ROI) of a subject and afirst couch supporting the subject. The first couch may have a pluralityof first positions reflected in the first image slice as a firstconformation. The first image slice may correspond to a stack of thirdimage slices affording axial views. The method may also includeobtaining a second image slice affording a sagittal view relating to theROI of the subject and a second couch supporting the subject. The secondcouch may have a plurality of second positions reflected in the secondimage slice as a second conformation. The method may also includedetermining, based on the first conformation and the secondconformation, a displacement field associated with the first image slicewith respect to the second image slice. The displacement field mayinclude a plurality of displacement components. Each third image sliceof the stack may correspond to one displacement component of theplurality of displacement components. The method may also includeadjusting, based on the displacement field, at least one third imageslice.

In some embodiments, the method may further include, for a third imageslice of the stack, moving, based on a corresponding displacementcomponent of the displacement field, a plurality of pixels in the thirdimage slice.

In some embodiments, the method may further include moving, based on thedisplacement field, spatial basis function representations correspondingto the imaging data.

In some embodiments, the first image slice may be acquired by a firstdevice and the second image slice may be acquired by a second devicedifferent from the first device.

In some embodiments, the first device may include an imaging deviceincluding at least one of a computed tomography (CT) scanner, a positronemission tomography (PET) scanner, a single photon emission computedtomography (SPECT) scanner, or a magnetic resonance (MR) scanner.

In some embodiments, the first device further may include aninterventional medical device, including at least one of a radiationtherapy (RT) treatment system, an ultrasound treatment system, a thermaltreatment system, or a surgical intervention system.

In some embodiments, the first image slice may include at least a pixelor spatial basis function representation corresponding to an isocenterof the first device, and the second image slice may include at least apixel or spatial basis function representation corresponding to anisocenter of the second device.

In some embodiments, the method may further include determining, basedon the first conformation and the second conformation, each displacementcomponent of the plurality of displacement components.

In some embodiments, the method may further include determining areference position of the second couch reflected in the second imageslice or the first couch reflected in the first image slice. Thereference position may correspond to an intersection between the firstconformation of the first couch and the second conformation of thesecond couch determined by registering the first image slice and thesecond image slice. The method may also include, for each first positionof the first couch, determining a first length of a portion of the firstcouch between the reference position and the first position reflected inthe first image slice. The method may also include determining, based onthe first length, the displacement component corresponding to the firstposition.

In some embodiments, the method may further include determining, basedon the first length, a second length between the reference position anda corrected first position of the first couch with respect to the secondconformation of the second couch. The method may also includedetermining, based on the first length and the second length, thedisplacement component corresponding to the first position.

In some embodiments, the second length may be equal to the first length.

In some embodiments, the second length may relate to an elasticextension of the first couch between the reference position and thefirst position.

In some embodiments, the method may further include determining, basedon the first position of the first couch and a corresponding secondposition of the second couch reflected in the second image slice, afirst deformation element in a vertical direction at the first positionof the first conformation with respect to the second conformation. Themethod may also include determining a first distance in a horizontaldirection between the reference position and the first position. Themethod may also include determining, based on the first deformationelement in the vertical direction and the first distance in thehorizontal direction, the first length.

In some embodiments, the method may further include determining therotation angle associated with the first position based on the firstlength, the first deformation element in the vertical direction, and thefirst distance in the horizontal direction.

In some embodiments, the method may further include, for each pair ofadjacent positions between the reference position and the first positionof the first couch reflected in the first image slice, determining asection length of a section of the first conformation between the eachpair of adjacent positions reflected in the first image slice. Themethod may also include obtaining the first length by summing thesection lengths.

In some embodiments, the method may further include determining areference position of the second couch reflected in the second imageslice or the first couch reflected in the first image slice. Thereference position may correspond to an intersection between the firstconformation of the first couch and the second conformation of thesecond couch determined by registering the first image slice and thesecond image slice. The method may also include, for each secondposition of the second couch, determining, based on the second positionof the second couch and a corresponding first position of the firstcouch reflected in the first image slice, a second deformation elementin a vertical direction of the first conformation with respect to thesecond conformation. The method may also include determining a seconddistance in a horizontal direction between the reference position andthe first position reflected in the first image slice. The method mayalso include determining, based on the second deformation element in thevertical direction and the second distance in the horizontal direction,the rotation angle associated with the first position.

According to another aspect of the present disclosure, a method forcouch sag compensation in a medical or imaging procedure is provided.The method may include obtaining a first image slice in a first viewrelating to a subject or a region of interest (ROI) of the subject and afirst conformation. The first image slice may correspond to a stack ofsecond image slices in a second view. The method may also includedetermining, based on the first conformation and a referenceconformation, a displacement field associated with the first image slicewith respect to the reference conformation, the displacement fieldincluding a plurality of displacement components. Each second imageslice of the stack may correspond to one displacement component of theplurality of displacement components.

In some embodiments, the method may further include adjusting, based onthe displacement field, spatial basis function representationscorresponding to imaging data. The imaging data may correspond to thestack of second image slices.

In some embodiments, the method may further include adjusting, based onthe displacement field, the stack of second image slices.

In some embodiments, the method may further include, for a second imageslice of the stack, moving, based on the corresponding displacementcomponent of the displacement field, a plurality of pixels in the secondimage slice.

In some embodiments, the first conformation may correspond to aplurality of first positions of a first couch reflected in the firstimage slice, and the reference conformation may correspond to aplurality of second positions of a second couch reflected in a thirdimage slice affording the first view.

In some embodiments, the first image slice may be acquired by a firstdevice and the third image slice may be acquired by a second devicedifferent from the first device.

In some embodiments, the first device or the second device may includean imaging device including at least one of a computed tomography (CT)scanner, a positron emission tomography (PET) scanner, a single photonemission computed tomography (SPECT) scanner, or a magnetic resonance(MR) scanner.

In some embodiments, the first device or the second device may furtherinclude an interventional medical device, including a radiation therapy(RT) treatment system, an ultrasound treatment system, a thermaltreatment system, or a surgical intervention system.

In some embodiments, the first image slice may include at least a pixelor a spatial basis function representation corresponding to an isocenterof the first device, and the third image slice may include at least apixel or a spatial basis function representation corresponding to anisocenter of the second device.

In some embodiments, the method may further include registering, basedon the displacement field, the stack of second image slices and a stackof fourth image slices affording the second view corresponding to thethird image slice.

In some embodiments, the method may further include registering, basedon a displacement component corresponding to a second image slice, acorresponding fourth image slice and the second image slice.

In some embodiments, a displacement component may include at least oneof a rotation element or a translation element.

In some embodiments, the first view may be perpendicular to the secondview.

According to another aspect of the present disclosure, a system mayinclude a storage device storing a set of instructions and one or moreprocessors in communication with the storage device. When executing theinstructions, one or more processors may be configured to cause thesystem to obtain a first set of imaging data affording a sagittal viewrelating to a subject and a first couch supporting the subject. Thefirst couch may have a plurality of first positions reflected in thefirst set of imaging data as a first conformation. The one or moreprocessors may also determine, based on the first conformation and areference conformation, a displacement field associated with the firstset of imaging data with respect to the reference conformation. The oneor more processors may also adjust, based on the displacement field, thefirst set of imaging data with respect to the reference conformation.The one or more processors may also obtain, based on the adjusted firstset of imaging data, an image of the subject with respect to thereference conformation.

According to another aspect of the present disclosure, a system forcouch sag compensation in a medical or imaging procedure is provided.The system may include a storage device storing a set of instructionsand one or more processors in communication with the storage device.When executing the instructions, one or more processors may beconfigured to cause the system to obtain a first image slice affording asagittal view relating to a region of interest (ROI) of a subject and afirst couch supporting the subject. The first couch may have a pluralityof first positions reflected in the first image slice as a firstconformation. The first image slice may correspond to a stack of thirdimage slices affording axial views. The one or more processors may alsoobtain a second image slice affording a sagittal view relating to theROI of the subject and a second couch supporting the subject. The secondcouch may have a plurality of second positions reflected in the secondimage slice as a second conformation. The one or more processors mayalso determine, based on the first conformation and the secondconformation, a displacement field associated with the first image slicewith respect to the second image slice. The displacement field mayinclude a plurality of displacement components. Each third image sliceof the stack may correspond to one displacement component of theplurality of displacement components. The one or more processors mayalso adjust, based on the displacement field, at least one third imageslice.

According to another aspect of the present disclosure, a system forcouch sag compensation in a medical or imaging procedure is provided.The system may include a storage device storing a set of instructionsand one or more processors in communication with the storage device.When executing the instructions, one or more processors may beconfigured to cause the system to obtain a first image slice in a firstview relating to a subject or a region of interest (ROI) of the subjectand a first conformation. The first image slice may correspond to astack of second image slices in a second view. The one or moreprocessors may also determine, based on the first conformation and areference conformation, a displacement field associated with the firstimage slice with respect to the reference conformation, the displacementfield including a plurality of displacement components. Each secondimage slice of the stack may correspond to one displacement component ofthe plurality of displacement components.

According to another aspect of the present disclosure, a non-transitorycomputer readable medium may include instructions. When executed by atleast one processor, the executions may cause the at least one processorto implement a method. The method may include obtaining a first set ofimaging data affording a sagittal view relating to a subject and a firstcouch supporting the subject. The first couch may have a plurality offirst positions reflected in the first set of imaging data as a firstconformation. The method may also include determining, based on thefirst conformation and a reference conformation, a displacement fieldassociated with the first set of imaging data with respect to thereference conformation. The method may also include adjusting, based onthe displacement field, the first set of imaging data with respect tothe reference conformation. The method may also include obtaining, basedon the adjusted first set of imaging data, an image of the subject withrespect to the reference conformation.

According to another aspect of the present disclosure, a non-transitorycomputer readable medium may include instructions. When executed by atleast one processor. The executions may cause the at least one processorto implement a method. The method may include obtaining a first imageslice affording a sagittal view relating to a region of interest (ROI)of a subject and a first couch supporting the subject. The first couchmay have a plurality of first positions reflected in the first imageslice as a first conformation. The first image slice may correspond to astack of third image slices affording axial views. The method may alsoinclude obtaining a second image slice affording a sagittal viewrelating to the ROI of the subject and a second couch supporting thesubject. The second couch may have a plurality of second positionsreflected in the second image slice as a second conformation. The methodmay also include determining, based on the first conformation and thesecond conformation, a displacement field associated with the firstimage slice with respect to the second image slice. The displacementfield may include a plurality of displacement components. Each thirdimage slice of the stack may correspond to one displacement component ofthe plurality of displacement components. The method may also includeadjusting, based on the displacement field, at least one third imageslice.

According to another aspect of the present disclosure, a non-transitorycomputer readable medium may include instructions. When executed by atleast one processor. The executions may cause the at least one processorto implement a method. The method may include obtaining a first imageslice in a first view relating to a subject or a region of interest(ROI) of the subject and a first conformation. The first image slice maycorrespond to a stack of second image slices in a second view. Themethod may also include determining, based on the first conformation anda reference conformation, a displacement field associated with the firstimage slice with respect to the reference conformation, the displacementfield including a plurality of displacement components. Each secondimage slice of the stack may correspond to one displacement component ofthe plurality of displacement components.

According to another aspect of the present disclosure, a system havingat least one processor and a storage device may include an image dataacquisition module, a displacement determination module, and an imagecorrection module. The image data acquisition module may be configuredto obtain a first set of imaging data affording a sagittal view relatingto a subject and a first couch supporting the subject. The first couchmay have a plurality of first positions reflected in the first set ofimaging data as a first conformation. The displacement determinationmodule may be configured to determine, based on the first conformationand a reference conformation, a displacement field associated with thefirst set of imaging data with respect to the reference conformation.The image correction module may be configured to adjust, based on thedisplacement field, the first set of imaging data with respect to thereference conformation. The image correction module may be configured toobtain, based on the adjusted first set of imaging data, an image of thesubject with respect to the reference conformation.

According to another aspect of the present disclosure, a system havingat least one processor and a storage device may include an image dataacquisition module, a displacement determination module, and an imagecorrection module. The image data acquisition module may be configuredto obtain a first image slice affording a sagittal view relating to aregion of interest (ROI) of a subject, a first couch supporting thesubject, a second image slice affording a sagittal view relating to theROI of the subject and a second couch supporting the subject. The firstcouch may have a plurality of first positions reflected in the firstimage slice as a first conformation. The first image slice maycorrespond to a stack of third image slices affording axial views. Thesecond couch may have a plurality of second positions reflected in thesecond image slice as a second conformation. The displacementdetermination module may be configured to determine, based on the firstconformation and the second conformation, a displacement fieldassociated with the first image slice with respect to the second imageslice. The displacement field may include a plurality of displacementcomponents. Each third image slice of the stack may correspond to onedisplacement component of the plurality of displacement components. Theimage correction module may be configured to adjust based on thedisplacement field, at least one third image slice.

According to another aspect of the present disclosure, a system havingat least one processor and a storage device may include an image dataacquisition module, and a displacement determination module. The imagedata acquisition module may be configured to obtain a first image slicein a first view relating to a subject or a region of interest (ROI) ofthe subject and a first conformation. The first image slice maycorrespond to a stack of second image slices in a second view. Thedisplacement determination module may be configured to determine, basedon the first conformation and a reference conformation, a displacementfield associated with the first image slice with respect to thereference conformation. The displacement field may include a pluralityof displacement components. Each second image slice of the stack maycorrespond to one displacement component of the plurality ofdisplacement components.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplaryembodiments. These exemplary embodiments are described in detail withreference to the drawings. These embodiments are non-limiting exemplaryembodiments, in which like reference numerals represent similarstructures throughout the several views of the drawings, and wherein:

FIG. 1 is a schematic diagram illustrating an exemplary diagnostic andtreatment system according to some embodiments of the presentdisclosure;

FIG. 2 illustrates a side view of an exemplary IGRT apparatus andassociated components according to some embodiments of the presentdisclosure;

FIG. 3 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary computing device on which theprocessing engine may be implemented according to some embodiments ofthe present disclosure;

FIG. 4 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary mobile device on which the terminalmay be implemented according to some embodiments of the presentdisclosure;

FIG. 5 is a block diagram illustrating an exemplary processing deviceaccording to some embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure;

FIG. 7 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure;

FIG. 8 is a flowchart illustrating an exemplary process for determininga displacement field associated with an image slice according to someembodiments of the present disclosure;

FIG. 9 is a schematic diagram illustrating an example for determining adisplacement component according to some embodiments of the presentdisclosure;

FIG. 10 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure;

FIGS. 11A-11C are images affording sagittal views relating to anexemplary phantom and a couch supporting the phantom according to someembodiments of the present disclosure; and

FIGS. 12A-12C are images relating to the same locally amplified regionin FIGS. 11A-11C according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant disclosure. However, it should be apparent to those skilledin the art that the present disclosure may be practiced without suchdetails. In other instances, well-known methods, procedures, systems,components, and/or circuitry have been described at a relativelyhigh-level, without detail, in order to avoid unnecessarily obscuringaspects of the present disclosure. Various modifications to thedisclosed embodiments will be readily apparent to those skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the present disclosure. Thus, the present disclosure is not limitedto the embodiments shown, but to be accorded the widest scope consistentwith the claims.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise,”“comprises,” and/or “comprising,” “include,” “includes,” and/or“including,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

It will be understood that the term “system,” “engine,” “unit,”“module,” and/or “block” used herein are one method to distinguishdifferent components, elements, parts, section or assembly of differentlevel in ascending order. However, the terms may be displaced by anotherexpression if they achieve the same purpose.

Generally, the word “module,” “unit,” or “block,” as used herein, refersto logic embodied in hardware or firmware, or to a collection ofsoftware instructions. A module, a unit, or a block described herein maybe implemented as software and/or hardware and may be stored in any typeof non-transitory computer-readable medium or another storage device. Insome embodiments, a software module/unit/block may be compiled andlinked into an executable program. It will be appreciated that softwaremodules can be callable from other modules/units/blocks or themselves,and/or may be invoked in response to detected events or interrupts.Software modules/units/blocks configured for execution on computingdevices (e.g., processor 310 as illustrated in FIG. 3 ) may be providedon a computer-readable medium, such as a compact disc, a digital videodisc, a flash drive, a magnetic disc, or any other tangible medium, oras a digital download (and can be originally stored in a compressed orinstallable format that needs installation, decompression, or decryptionprior to execution). Such software code may be stored, partially orfully, on a storage device of the executing computing device, forexecution by the computing device. Software instructions may be embeddedin firmware, such as an EPROM. It will be further appreciated thathardware modules/units/blocks may be included in connected logiccomponents, such as gates and flip-flops, and/or can be included ofprogrammable units, such as programmable gate arrays or processors. Themodules/units/blocks or computing device functionality described hereinmay be implemented as software modules/units/blocks but may berepresented in hardware or firmware. In general, themodules/units/blocks described herein refer to logicalmodules/units/blocks that may be combined with othermodules/units/blocks or divided into sub-modules/sub-units/sub-blocksdespite their physical organization or storage. The description mayapply to a system, an engine, or a portion thereof.

It will be understood that when a unit, engine, module or block isreferred to as being “on,” “connected to,” or “coupled to,” anotherunit, engine, module, or block, it may be directly on, connected orcoupled to, or communicate with the other unit, engine, module, orblock, or an intervening unit, engine, module, or block may be present,unless the context clearly indicates otherwise. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

These and other features, and characteristics of the present disclosure,as well as the methods of operation and functions of the relatedelements of structure and the combination of parts and economies ofmanufacture, may become more apparent upon consideration of thefollowing description with reference to the accompanying drawings, allof which form a part of this disclosure. It is to be expresslyunderstood, however, that the drawings are for the purpose ofillustration and description only and are not intended to limit thescope of the present disclosure. It is understood that the drawings arenot to scale.

The flowcharts used in the present disclosure illustrate operations thatsystems implement according to some embodiments of the presentdisclosure. It is to be expressly understood, the operations of theflowcharts may be implemented not in order. Conversely, the operationsmay be implemented in inverted order, or simultaneously. Moreover, oneor more other operations may be added to the flowcharts. One or moreoperations may be removed from the flowcharts.

Provided herein are systems and methods for medical diagnostic and/ortreatment. In some embodiments, the medical system may include andiagnostic system. The diagnostic system may include a multi-modalityimaging system. The multi-modality imaging system may include, forexample, a computed tomography-positron emission tomography (CT-PET)system, a computed tomography-positron emission tomography-magneticresonance imaging (CT-MRI) system, a X-ray imaging-magnetic resonanceimaging (X-ray-MRI) system, a positron emission tomography-X-ray imaging(PET-X-ray) system, a single photon emission computedtomography-magnetic resonance imaging (SPECT-MRI) system, a digitalsubtraction angiography-magnetic resonance imaging (DSA-MRI) system, orthe like, or a combination thereof. In some embodiments, the medicalsystem may include a diagnostic and treatment system. The diagnostic andtreatment system may include a treatment plan system (TPS), animage-guide radio therapy (IGRT) system, etc. Merely by way of example,the image guided radio therapy (IGRT) system may include, for example, aCT guided radiotherapy system, an MRI guided radiotherapy system, etc.

The present disclosure relates to a system and method for couch sagcompensation in a medical or imaging procedure. The method may includeobtaining a first set of imaging data affording a sagittal view relatingto a subject and a couch supporting the subject. The couch may have aplurality of first positions reflected in the first set of imaging dataas a first conformation. The method may further include determining adisplacement field associated with the first set of imaging data withrespect to a reference conformation based on the first conformation andthe reference conformation. The first set of imaging data with respectto the reference conformation may be adjusted based on the displacementfield. Then, an image of the subject with respect to the referenceconformation may be obtained based on the adjusted first set of imagingdata.

It should be noted that the diagnostic and treatment system 100described below is merely provided for illustration purposes, and notintended to limit the scope of the present disclosure. For personshaving ordinary skills in the art, a certain amount of variations,changes, and/or modifications may be deducted under the guidance of thepresent disclosure. Those variations, changes, and/or modifications donot depart from the scope of the present disclosure.

FIG. 1 is a schematic diagram illustrating an exemplary diagnostic andtreatment system 100 according to some embodiments of the presentdisclosure. As shown, the diagnostic and treatment system 100 mayinclude a medical apparatus 110, a processing device 120, storage 130,one or more terminal(s) 140, and a network 150. In some embodiments, themedical apparatus 110, the processing device 120, the storage 130,and/or the terminal(s) 140 may be connected to and/or communicate witheach other via a wireless connection (e.g., the network 150), a wiredconnection, or any combination thereof. The connections between thecomponents in the diagnostic and treatment system 100 may vary. Merelyby way of example, the medical apparatus 110 may be connected to theprocessing device 120 through the network 150, as illustrated in FIG. 1. As another example, the medical apparatus 110 may be connected to theprocessing device 120 directly. As a further example, the storage 130may be connected to the processing device 120 through the network 150,as illustrated in FIG. 1 , or connected to the processing device 120directly. As still a further example, the terminal(s) 140 may beconnected to the processing device 120 through the network 150, asillustrated in FIG. 1 , or connected to the processing device 120directly.

The medical apparatus 110 may acquire imaging data relating to at leastone part of a subject. The imaging data relating to at least one part ofa subject may include an image (e.g., an image slice), projection data,or a combination thereof. In some embodiments, the imaging data may be atwo-dimensional (2D) imaging data, a three-dimensional (3D) imagingdata, a four-dimensional (4D) imaging data, or the like, or anycombination thereof. In some embodiments, the imaging data may afford asagittal view, an axial view, a coronal view, etc. The subject may bebiological or non-biological. For example, the subject may include apatient, a man-made object, etc. As another example, the subject mayinclude a specific portion, organ, and/or tissue of the patient. Forexample, the subject may include the head, the neck, the thorax, theheart, the stomach, a blood vessel, soft tissue, a tumor, nodules, orthe like, or any combination thereof.

In some embodiments, the medical apparatus 110 may be a single-modalityapparatus. For example, the medical apparatus 110 may include an imagingdevice 112. The imaging device 112 may be configured to provide theimaging data for determining the at least one part of the subject (e.g.,an anatomical point). The imaging device 112 may include a CT device, aCBCT device, a PET device, a volume CT device, an MRI device, a SPECTdevice, or the like, or a combination thereof. The medical apparatus 110may further include a couch 116. The couch 116 may be configured tosupport and/or transfer the at least one part of the subject to, forexample, a scanning region of the imaging device 112.

In some embodiments, the medical apparatus 110 may be a multi-modality(e.g., two-modality) apparatus. For example, the imaging device 112 mayinclude a CT-PET device, a CT-MRI device, a PET-MRI device, a SPECT-CTdevice, or the like, or a combination thereof. As another example, themedical apparatus 110 may further include an interventional medicaldevice. Exemplary interventional medical devices may include a radiationtherapy (RT) device, an ultrasound treatment device, a thermal treatmentdevice, a surgical intervention device, or the like, or a combinationthereof. In some embodiments, the imaging device 112 and theinterventional medical device may be located separately from each other.In some embodiments, the imaging device 112 may be coupled with theinterventional medical device. The imaging device 112 and theinterventional medical device may share a same bore that may be used toaccommodate a subject to be imaged and/or treated. More descriptions ofthe medical apparatus 110 may be found elsewhere in the presentdisclosure. See for example, FIG. 2 and the descriptions thereof.

The processing device 120 may process data and/or information obtainedfrom the medical apparatus 110, the storage 130, and/or the terminal(s)140. For example, the processing device 120 may determine a displacementfield associated with a stack of image slices. The displacement fieldmay include a plurality of displacement components. An image slice ofthe stack may correspond to one displacement component of the pluralityof displacement components. As another example, the processing device120 may adjust the stack of image slices based on the displacementfield.

In some embodiments, the processing device 120 may be a single server ora server group. The server group may be centralized or distributed. Insome embodiments, the processing device 120 may be local or remote. Forexample, the processing device 120 may access information and/or datafrom the medical apparatus 110, the storage 130, and/or the terminal(s)140 via the network 150. As another example, the processing device 120may be directly connected to the medical apparatus 110, the terminal(s)140, and/or the storage 130 to access information and/or data. In someembodiments, the processing device 120 may be implemented on a cloudplatform. For example, the cloud platform may include a private cloud, apublic cloud, a hybrid cloud, a community cloud, a distributed cloud, aninter-cloud, a multi-cloud, or the like, or any combination thereof. Insome embodiments, the processing device 120 may be implemented by amobile device 400 having one or more components as described inconnection with FIG. 4 .

The storage 130 may store data, instructions, and/or any otherinformation. In some embodiments, the storage 130 may store dataobtained from the medical apparatus 110, the processing device 120,and/or the terminal(s) 140. In some embodiments, the storage 130 maystore data and/or instructions that the processing device 120 mayexecute or use to perform exemplary methods described in the presentdisclosure. In some embodiments, the storage 130 may include a massstorage, a removable storage, a volatile read-and-write memory, aread-only memory (ROM), or the like, or any combination thereof.Exemplary mass storage may include a magnetic disk, an optical disk, asolid-state drive, etc. Exemplary removable storage may include a flashdrive, a floppy disk, an optical disk, a memory card, a zip disk, amagnetic tape, etc. Exemplary volatile read-and-write memory may includea random access memory (RAM). Exemplary RAM may include a dynamic RAM(DRAM), a double date rate synchronous dynamic RAM (DDR SDRAM), a staticRAM (SRAM), a thyristor RAM (T-RAM), and a zero-capacitor RAM (Z-RAM),etc. Exemplary ROM may include a mask ROM (MROM), a programmable ROM(PROM), an erasable programmable ROM (EPROM), an electrically erasableprogrammable ROM (EEPROM), a compact disk ROM (CD-ROM), and a digitalversatile disk ROM, etc. In some embodiments, the storage 130 may beimplemented on a cloud platform as described elsewhere in thedisclosure.

In some embodiments, the storage 130 may be connected to the network 150to communicate with one or more other components in the diagnostic andtreatment system 100 (e.g., the processing device 120, the terminal(s)140, etc.). One or more components in the diagnostic and treatmentsystem 100 may access the data or instructions stored in the storage 130via the network 150. In some embodiments, the storage 130 may be part ofthe processing device 120.

The terminal(s) 140 may be connected to and/or communicate with themedical apparatus 110, the processing device 120, and/or the storage130. For example, the terminal(s) 140 may obtain a processed image fromthe processing device 120. As another example, the terminal(s) 140 mayobtain imaging data acquired via the medical apparatus 110 and transmitthe imaging data to the processing device 120 to be processed. In someembodiments, the terminal(s) 140 may include a mobile device 140-1, atablet computer 140-2, . . . , a laptop computer 140-N, or the like, orany combination thereof. For example, the mobile device 140-1 mayinclude a mobile phone, a personal digital assistant (PDA), a gamingdevice, a navigation device, a point of sale (POS) device, a laptop, atablet computer, or the like, or any combination thereof. In someembodiments, the terminal(s) 140 may include an input device, an outputdevice, etc. The input device may include alphanumeric and other keysthat may be input via a keyboard, a touch screen (for example, withhaptics or tactile feedback), a speech input, an eye tracking input, abrain monitoring system, or any other comparable input mechanism. Theinput information received through the input device may be transmittedto the processing device 120 via, for example, a bus, for furtherprocessing. Other types of the input device may include a cursor controldevice, such as a mouse, a trackball, or cursor direction keys, etc. Theoutput device may include a display, a speaker, a printer, or the like,or any combination thereof. In some embodiments, the terminal(s) 140 maybe part of the processing device 120.

The network 150 may include any suitable network that can facilitateexchange of information and/or data for the diagnostic and treatmentsystem 100. In some embodiments, one or more components of thediagnostic and treatment system 100 (e.g., the medical apparatus 110,the processing device 120, the storage 130, the terminal(s) 140, etc.)may communicate information and/or data with one or more othercomponents of the diagnostic and treatment system 100 via the network150. For example, the processing device 120 may obtain imaging data fromthe medical apparatus 110 via the network 150. As another example, theprocessing device 120 may obtain user instruction(s) from theterminal(s) 140 via the network 150. The network 150 may be and/orinclude a public network (e.g., the Internet), a private network (e.g.,a local area network (LAN), a wide area network (WAN)), etc.), a wirednetwork (e.g., an Ethernet network), a wireless network (e.g., an 802.11network, a Wi-Fi network, etc.), a cellular network (e.g., a Long TermEvolution (LTE) network), a frame relay network, a virtual privatenetwork (VPN), a satellite network, a telephone network, routers, hubs,witches, server computers, and/or any combination thereof. For example,the network 150 may include a cable network, a wireline network, afiber-optic network, a telecommunications network, an intranet, awireless local area network (WLAN), a metropolitan area network (MAN), apublic telephone switched network (PSTN), a Bluetooth™ network, aZigBee™ network, a near field communication (NFC) network, or the like,or any combination thereof. In some embodiments, the network 150 mayinclude one or more network access points. For example, the network 150may include wired and/or wireless network access points such as basestations and/or internet exchange points through which one or morecomponents of the diagnostic and treatment system 100 may be connectedto the network 150 to exchange data and/or information.

This description is intended to be illustrative, and not to limit thescope of the present disclosure. Many alternatives, modifications, andvariations will be apparent to those skilled in the art. The features,structures, methods, and other characteristics of the exemplaryembodiments described herein may be combined in various ways to obtainadditional and/or alternative exemplary embodiments. For example, thestorage 130 may be a data storage including cloud computing platforms,such as, public cloud, private cloud, community, and hybrid clouds, etc.However, those variations and modifications do not depart the scope ofthe present disclosure.

FIG. 2 illustrates a side view of an exemplary IGRT apparatus 200 andassociated components according to some embodiments of the presentdisclosure. The IGRT apparatus 200 may be an exemplary medical apparatus110 as shown in FIG. 1 . The IGRT apparatus 200 may include an imagingdevice 220, a RT device 240, and a couch 260.

The imaging device 220 may acquire imaging data relating to at least onepart of a subject and/or the couch 260 via scanning the at least onepart of the subject. The imaging device 220 may include a CT scanner, aPET scanner, a SPECT scanner, an MRI scanner, or the like, or acombination thereof. In some embodiments, the imaging device 220 mayhave an isocenter 223. As used herein, the isocenter 223 of the imagingdevice 220 may refer to a point through which central rays of aradiation source of the imaging device 220 passes during a medicalprocess.

The RT device 240 may be used for treatment, for example, performing aradio therapy on the at least one part of the subject determined basedon the CT image. The RT device 240 may include a cyclotron, an inductionaccelerator, a linear accelerator (LINAC), etc. In some embodiments, theimaging device 220 and the RT device 240 may be set back to back oradjacent to each other as illustrated in FIG. 2 . The imaging device 220and the RT device 240 may have a same rotation axis. Specifically, theimaging device 220 may be coupled with the RT device 240. In someembodiments, the imaging device 220 and the RT device 240 may be setseparately from each other. The RT device 240 may have an isocenter 243.As used herein, the isocenter 243 of the RT device 240 may refer to apoint through which central rays of a radiation source of the RT device240 passes during a medical process. The isocenter 223 of the imagingdevice 220 and the isocenter 243 of the RT device 240 may lie on a samehorizontal longitudinal line.

The couch 260 may be configured to support and/or transfer the at leastone part of the subject. The couch 260 may include a support roller 263,a table top 265, a table top carrier 267, a table base 269, or the like,or any combination thereof. The support roller 263 may support the tabletop carrier 267. The table top carrier 267 may support the table top265. The table top 265 may extend along the longitudinal direction ofthe couch.

The couch 260 may move in any direction. For example, a longitudinaldirection (i.e., along a long axis of table top 265 in the plane of thetable top 265), a lateral direction (i.e., along a short axis of thetable top 265 in the plane of the table top 265), a direction (alsoreferred to as a vertical direction) perpendicular to the longitudinaldirection and lateral direction, or a direction oblique to thelongitudinal direction and/or the lateral direction. The movement of thecouch 260 may be driven manually or by, for example, a motor. In someembodiments, the longitudinal direction may be described as Y direction.The vertical direction may be described as the Z direction. The Ydirection and the Z direction may be within the plane containing aradiotherapy source of the RT device 240 and the rotation centers of theRT device 240 and the imaging device 220.

In some embodiments, the imaging device 220 and the RT device 240 mayshare the couch 260. An object supported on the couch 260 may go throughboth an imaging scan and a radiation therapy during which the objectdoes not need to change from one couch to a different couch. Forexample, the couch 260 may be used to support an object at an RTposition for a radiation therapy. As another example, the couch 260 maybe used to transfer an object from an RT position to an imaging positionand/or support the object at the imaging position for imaging. As usedherein, an RT position may refer to a position that is within a workarea of the RT device 240. A CT position may refer to a position that iswithin a work area of the imaging device 220.

The couch 260 (e.g., the table top 265) may include a plurality ofpositions. While the couch 260 extends from an RT position under theradiation source of the RT device 240 and then further into an imagingposition under the imaging device 220, the couch 260 may deform. Thedeformation of a specific position of the table top 265 extending beyondthe support roller 263 may change as the table top 265 extends orretracts. The deformation element at the specific position of the tabletop 265 may increase along with the increase of the amount of extension.In some embodiments, the deformation of a position of the table top 265located at the support roller 263 may be neglected. The position of thetable top 265 located at the support roller 263 may be designated as areference position of the couch 260. For each of the plurality ofpositions of the table top 265, the deformation of the couch 260 may bedifferent when the couch 260 is located at a specific imaging positionor RT position.

In some embodiments, the deformation of a couch corresponding to each ofthe plurality of positions of the table top 265 may be described interms of a rotation angle (e.g., a as shown in FIG. 2 ) and adeformation element (e.g., the amount of displacement of a couch in thevertical direction, etc.) associated with the each of the plurality ofpositions of the table top 265. The rotation angle may be an anglebetween the dashed line 210 and the deformed section of the table top265 that extends beyond the supporting structure (e.g., the table topcarrier 267) of the table top 265. In some embodiments, the deformationof a couch may be described in terms of a displacement field withrespect to a reference conformation of the couch (e.g., a conformationof the couch without deformation). The displacement field may include aplurality of displacement components. Each of the plurality ofdisplacement components may correspond to one of the plurality ofpositions of the table top 265 with respect to the referenceconformation at the one of the plurality of positions. More descriptionsof the displacement field and/or the rotation angles may be foundelsewhere in the present disclosure. See for example, FIGS. 6-10 and thedescriptions thereof.

FIG. 3 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary computing device 300 on which theprocessing device 120 may be implemented according to some embodimentsof the present disclosure. As illustrated in FIG. 3 , the computingdevice 300 may include a processor 310, a storage 320, an input/output(I/O) 330, and a communication port 340.

The processor 310 may execute computer instructions (e.g., program code)and perform functions of the processing device 120 in accordance withtechniques described herein. The computer instructions may include, forexample, routines, programs, objects, components, data structures,procedures, modules, and functions, which perform particular functionsdescribed herein. For example, the processor 310 may process imagingdata obtained from the medical apparatus 110, the storage 130,terminal(s) 140, and/or any other component of the diagnostic andtreatment system 100. In some embodiments, the processor 310 may includeone or more hardware processors, such as a microcontroller, amicroprocessor, a reduced instruction set computer (RISC), anapplication specific integrated circuits (ASICs), anapplication-specific instruction-set processor (ASIP), a centralprocessing unit (CPU), a graphics processing unit (GPU), a physicsprocessing unit (PPU), a microcontroller unit, a digital signalprocessor (DSP), a field programmable gate array (FPGA), an advancedRISC machine (ARM), a programmable logic device (PLD), any circuit orprocessor capable of executing one or more functions, or the like, or acombinations thereof.

Merely for illustration, only one processor is described in thecomputing device 300. However, it should be noted that the computingdevice 300 in the present disclosure may also include multipleprocessors, thus operations and/or method steps that are performed byone processor as described in the present disclosure may also be jointlyor separately performed by the multiple processors. For example, if inthe present disclosure the processor of the computing device 300executes both operation A and operation B, it should be understood thatoperation A and operation B may also be performed by two or moredifferent processors jointly or separately in the computing device 300(e.g., a first processor executes operation A and a second processorexecutes operation B, or the first and second processors jointly executeoperations A and B).

The storage 320 may store data/information obtained from the medicalapparatus 110, the storage 130, the terminal(s) 140, and/or any othercomponent of the diagnostic and treatment system 100. In someembodiments, the storage 320 may include a mass storage, a removablestorage, a volatile read-and-write memory, a read-only memory (ROM), orthe like, or any combination thereof. For example, the mass storage mayinclude a magnetic disk, an optical disk, a solid-state drive, etc. Theremovable storage may include a flash drive, a floppy disk, an opticaldisk, a memory card, a zip disk, a magnetic tape, etc. The volatileread-and-write memory may include a random access memory (RAM). The RAMmay include a dynamic RAM (DRAM), a double date rate synchronous dynamicRAM (DDR SDRAM), a static RAM (SRAM), a thyristor RAM (T-RAM), and azero-capacitor RAM (Z-RAM), etc. The ROM may include a mask ROM (MROM),a programmable ROM (PROM), an erasable programmable ROM (EPROM), anelectrically erasable programmable ROM (EEPROM), a compact disk ROM(CD-ROM), and a digital versatile disk ROM, etc. In some embodiments,the storage 320 may store one or more programs and/or instructions toperform exemplary methods described in the present disclosure. Forexample, the storage 320 may store a program for the processing device120 for determining a target flip angle schedule.

The I/O 330 may input and/or output signals, data, information, etc. Insome embodiments, the I/O 330 may enable a user interaction with theprocessing device 120. In some embodiments, the I/O 330 may include aninput device and an output device. Examples of the input device mayinclude a keyboard, a mouse, a touch screen, a microphone, or the like,or any combination thereof. Examples of the output device may include adisplay device, a loudspeaker, a printer, a projector, or the like, orany combination thereof. Examples of the display device may include aliquid crystal display (LCD), a light-emitting diode (LED)-baseddisplay, a flat panel display, a curved screen, a television device, acathode ray tube (CRT), a touch screen, or the like, or any combinationthereof.

The communication port 340 may be connected to a network (e.g., thenetwork 150) to facilitate data communications. The communication port340 may establish connections between the processing device 120 and themedical apparatus 110, the storage 130, and/or the terminal(s) 140. Theconnection may be a wired connection, a wireless connection, any othercommunication connection that can enable data transmission and/orreception, and/or a combination of these connections. The wiredconnection may include, for example, an electrical cable, an opticalcable, a telephone wire, or the like, or any combination thereof. Thewireless connection may include, for example, a Bluetooth™ link, aWi-Fi™ link, a WiMax™ link, a WLAN link, a ZigBee link, a mobile networklink (e.g., 3G, 4G, 5G, etc.), or the like, or any combination thereof.In some embodiments, the communication port 340 may be and/or include astandardized communication port, such as RS232, RS485, etc. In someembodiments, the communication port 340 may be a specially designedcommunication port. For example, the communication port 340 may bedesigned in accordance with the digital imaging and communications inmedicine (DICOM) protocol.

FIG. 4 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary mobile device 400 on which theterminal(s) 140 may be implemented according to some embodiments of thepresent disclosure. As illustrated in FIG. 4 , the mobile device 400 mayinclude a communication platform 410, a display 420, a graphicprocessing unit (GPU) 430, a central processing unit (CPU) 440, an I/O450, a memory 460, and a storage 490. In some embodiments, any othersuitable component, including but not limited to a system bus or acontroller (not shown), may also be included in the mobile device 400.In some embodiments, a mobile operating system 470 (e.g., iOS™,Android™, Windows Phone™, etc.) and one or more applications 480 may beloaded into the memory 460 from the storage 490 in order to be executedby the CPU 440. The applications 480 may include a browser or any othersuitable mobile apps for receiving and rendering information relating toimage processing or other information from the processing device 120.User interactions with the information stream may be achieved via theI/O 450 and provided to the processing device 120 and/or othercomponents of the diagnostic and treatment system 100 via the network150.

To implement various modules, units, and their functionalities describedin the present disclosure, computer hardware platforms may be used asthe hardware platform(s) for one or more of the elements describedherein. A computer with user interface elements may be used to implementa personal computer (PC) or any other type of work station or terminaldevice. A computer may also act as a server if appropriately programmed.

FIG. 5 is a block diagram illustrating an exemplary processing device120 according to some embodiments of the present disclosure. Theprocessing device 120 may be implemented on the computing device 300(e.g., the processor 310) illustrated in FIG. 3 or the mobile device 400as illustrated in FIG. 4 . The processing device 120 may include animage data acquisition module 510, a displacement determination module520, an image correction module 530, and a storage module 540.

The image data acquisition module 510 may obtain imaging data relatingto a subject and/or a couch supporting the subject. The imaging datarelating to a subject and/or a couch supporting the subject may bepresented as a stack of image slices affording sagittal views, a stackof image slices affording coronal views, a stack of image slicesaffording axial views, spatial basis function representations, or acombination thereof. In some embodiments, the imaging data may beobtained from the medical apparatus 110, the storage 130, theterminal(s) 140, the storage module 540, or any other external storage.For example, the imaging data may be obtained from the medical apparatus110 generated by the imaging device 112 scanning the subject.

The displacement determination module 520 may determine a displacementfield associated with imaging data. In some embodiments, thedisplacement field associated with imaging data may include a pluralityof displacement components. The displacement field associated withimages in a view corresponding to the imaging data may be converted to adisplacement field associated with images corresponding to the sameimaging data in a different view. For instance, the displacement fieldassociated with images in the sagittal view corresponding to the imagingdata may be converted to a displacement field associated with imagescorresponding to the same imaging data in the axial view and/or in thecoronal view. The imaging data adjusted based on a displacement fieldassociated with images in a view (e.g., in an axial view) may be used toprovide adjusted images in another view (e.g., in a coronal view). Forinstance, the imaging data adjusted based on a displacement fieldassociated with images in the sagittal view may be used to provideadjusted images in the axial view and/or the coronal view. Forillustration purposes, the displacement field associated with images inthe sagittal view is described below. It is understood it is notintended to limit the scope of the present disclosure. A displacementcomponent of the plurality of displacement components may correspond toa position of the plurality of positions of a couch. In someembodiments, the displacement determination module 520 may determine adisplacement component based on a first conformation of the couchreflected in the imaging data and a reference conformation. In someembodiments, a displacement component corresponding to a position of thecouch may include a rotation angle associated with the position. Thedisplacement determination module 520 may determine the rotation angleassociated with the position.

The image correction module 530 may adjust the imaging data based on thedisplacement field associated with the imaging data. In someembodiments, the image correction module 530 may move the pixels orvoxels in the imaging data based on the displacement field. In someembodiments, the image correction module 530 may move a plurality ofspatial basis function representations associated with the imaging databased on the displacement field. In some embodiments, the imagecorrection module 530 may obtain an image based on the adjusted imagingdata.

The storage module 540 may store information. The information mayinclude programs, software, algorithms, data, text, number, images andsome other information. For example, the information may include imagingdata, a displacement field associated with the imaging data, etc. Thedisplacement field may include a plurality of displacement componentsassociated with the imaging data.

It should be noted that the above description of the processing device120 is provided for the purpose of illustration, and is not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations and modifications may be madeunder the teaching of the present disclosure. However, those variationsand modifications do not depart from the scope of the presentdisclosure.

FIG. 6 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure.In some embodiments, one or more operations of process 600 illustratedin FIG. 6 may be implemented in the diagnostic and treatment system 100illustrated in FIG. 1 . For example, process 600 illustrated in FIG. 6may be stored in the storage 130 in the form of instructions, andinvoked and/or executed by the processing device 120 (e.g., theprocessor 310 of the computing device 300 as illustrated in FIG. 3 , theGPU 430 or CPU 440 of the mobile device 400 as illustrated in FIG. 4 ).

In 602, a first set of imaging data may be obtained. The first set ofimaging data may afford a sagittal view relating to a subject and acouch supporting the subject. Operation 602 may be performed by theimage data acquisition module 510. The couch may have a plurality offirst positions reflected in the first set of imaging data as a firstconformation. For brevity, a position of a couch as used herein mayrefer to a physical portion of the couch, or the corresponding portionas reflect in the imaging data or in an image (or image slice). Forbrevity, a conformation of a couch may refer to a contour or outline ofthe couch physically, or the corresponding contour or outline as reflectin the imaging data or in an image (or image slice). For example, thefirst conformation of the couch may refer to the shape or outline of thecouch supporting the subject reflected in the first set of imaging data.The first conformation of the couch may relate to the configurations ofthe couch at various positions. The first conformation of the couch maydepend on factors including, e.g., its supporting structure, thematerial of the couch, the loading placed on the couch, or the like, ora combination thereof. In some embodiments, the first set of imagingdata may be obtained from the medical apparatus 110, the storage 130,the terminal(s) 140, the storage module 540, or any other externalstorage. For example, the first set of imaging data may be obtained fromthe medical apparatus 110 generated by the imaging device 112 scanningthe subject. The imaging device 112 may include a CT device, a CBCTdevice, a PET device, a volume CT device, an MRI device, a SPECT device,or the like, or a combination thereof.

In some embodiments, the first set of imaging data may be presented inthe form of spatial basis function representations relating to thesubject and the couch. Each of the plurality of first positions or thefirst conformation at the each of the plurality of first positionsreflected in the first set of imaging data may correspond to one of theplurality of spatial basis function representations. The spatial basisfunction representations relating to the subject and the couch may referto information of a first image (or referred to as a first image slice)relating to the subject and the couch in a spatial domain representedbased on multiple spatial basis functions in a transform domain. Thespatial basis function representations (i.e., the first set of imagingdata) relating to the subject and the couch may be obtained byperforming a positive transformation on the first image relating to thesubject and the couch based on a plurality of spatial basis functions,then the first image in the spatial domain may be transformed into thefirst set of imaging data in the transform domain. As used herein, thespatial basis functions may be also referred to as basis vectors,dictionary elements, elementary functions, etc. The spatial basisfunction representations (i.e., the first set of imaging data) in thetransform domain may be transformed into the first image in the spatialdomain by performing a negative transformation on the spatial basisfunction representations (i.e., the first set of imaging data) based onthe plurality of spatial basis functions. Exemplary transformations mayinclude a Fourier transform (FT), a Wavelet transform (WT), independentcomponent analysis (ICA), sparse coding (SC), a Gabor transform, or thelike, or a combination thereof. Exemplary transformations may include aFourier transform (FT), a Wavelet transform (WT), an independentcomponent analysis (ICA), sparse coding (SC), a Gabor transform, or thelike, or a combination thereof.

In 604, a displacement field associated with the first set of imagingdata with respect to a reference conformation may be determined based onthe first conformation and a reference conformation. Operation 604 maybe performed by the displacement determination module 520. As usedherein, the reference conformation may be also referred to as a modelconformation of the couch. For example, the first conformation may bereflected in the first image affording a sagittal view as a first line(e.g., line 920 as shown in FIG. 9 ). The reference conformation may bereflected in the first image affording the sagittal view as a secondline (e.g., line 910 as shown in FIG. 9 ). In some embodiments, thesecond line may be a straight horizontal line. The second line (e.g.,line 910 as shown in FIG. 9 ) may intersect with the first line (e.g.,line 920 as shown in FIG. 9 ) at a reference point (e.g., point P_(r) asshown in FIG. 9 ) corresponding to the reference position of the couch.The reference conformation and the first conformation of the couchreflected in the first set of imaging data may be the same at thereference position. The deformation or configuration of the couch withthe reference conformation may be the same as the deformation orconfiguration of the couch with the first conformation at the referenceposition. In some embodiments, the reference conformation of the couchmay be determined by determining a reference position of the couchreflected in the first set of imaging data. The reference conformationof the couch reflected in the first set of imaging data (i.e., thesecond line) may be determined by determining a straight horizontal linethrough the reference point on the first line.

In some embodiments, the reference conformation may include aconformation of the couch without deformation. The first set of imagingdata may be adjusted based on the displacement field corresponding tothe reference conformation so that the adjusted first set of imagingdata may present the subject or a portion thereof supported on a couchwithout deformation.

In some embodiments, the reference conformation of the couch may includea conformation of the couch with deformation that is different fromdeformation of the couch corresponding to the first conformation. Insome embodiments, the reference conformation of a couch may be obtainedfrom a second set of imaging data affording a sagittal view relating tothe couch. The second set of imaging data may be acquired when the couchsupports the subject or not. In some embodiments, the couch reflected inthe second set of imaging data may be the same as the couch reflected inthe first set of imaging data. For instance, the first set of imagingdata and the second set of imaging data may be acquired by scanning thesubject using a same imaging device including a couch for supporting thesubject (e.g., a same CT scanner in a same IGRT device, a same imagingdevice 112 of the medical apparatus 110). In some embodiments, the couchreflected in the second set of imaging data may be different from thecouch reflected in the first set of imaging data. For instance, thefirst set of imaging data and the second set of imaging data may beacquired by scanning the subject using different imaging devices havingdifferent couches for supporting the subject, e.g., a CT scanner in anIGRT device and a different CT scanner. The first set of imaging datamay be adjusted based on the displacement field corresponding to thereference conformation so that the adjusted first set of imaging datarelating to the subject or a portion thereof may be registered and/orcompared with the second set of imaging data relating to the samesubject or a portion thereof.

As used herein, the displacement field associated with the first set ofimaging data may reflect changes of positions of the couch reflected inthe first set of imaging data (e.g., the first conformation) withrespect to the reference conformation. The displacement field associatedwith the first set of imaging data may also reflect changes of positionsof the subject corresponding to and represented by the changes of thefirst conformation with respect to the reference conformation.

The displacement field may include a plurality of displacementcomponents. A displacement component may correspond to a position or aspatial basis representation function of the couch. A displacementcomponent may reflect a local displacement at a position or correspondto a spatial basis representation function of the couch. Thedisplacement component associated with the first position may include adistance from the first position to a corrected first position of thefirst couch with respect to the reference conformation and a directionfrom the first position to the corrected first position of the firstcouch with respect to the reference conformation reflected in the firstset of imaging data. Two displacement components corresponding to twodifferent first positions or two different spatial basis functionrepresentations respectively may be different. A displacement componentassociated with the reference position may equal 0. In other words, thedistance from the reference position to a corrected reference positionof the first couch with respect to the reference conformation may equal0. The first conformation may coincide with the reference conformationat the reference position. In some embodiments, a distance between afirst position and the reference position reflected in the first set ofimaging data and a distance between an adjacent first positon and thereference position reflected in the reflected in the first set ofimaging data may be different. In some embodiments, these distances maychange as a function of the first positions nonlinearly. See, e.g., FIG.9 . In some embodiments, a distance from the first position to acorrected first position of the first couch with respect to thereference conformation may relate to a distance between the referenceposition of the couch and the first position of the couch. In someembodiments, the distance between the reference position of the couchand the first position of the couch may be assessed in terms of orapproximated by a length of a portion of the couch between the referenceposition and the first position of the couch. Further, the referenceposition may correspond to a spatial basis function representation. Thefirst position may correspond to a spatial basis functionrepresentation. The displacement component associated with the firstposition may relate to a distance (e.g., the length of a portion of thecouch between the reference position and the first position of thecouch) between the spatial basis function representation correspondingto the first position and the reference basis function representationcorresponding to the reference position.

In some embodiments, a direction from the first position to thecorrected first position of the first couch with respect to thereference conformation may be defined by a rotation angle associatedwith the first positon. The displacement field associated with the firstof imaging data may include a plurality of rotation angles as describedelsewhere in the present disclosure (e.g., FIG. 2 , and the descriptionsthereof). A rotation angle may correspond to a first position of thecouch. In some embodiments, a rotation angle may relate to a spatialbasis function representation associated with the first set of imagingdata. Two rotation angles corresponding to two different first positionsor two different spatial basis function representations respectively maybe different. In some embodiments, the rotation angle associated with afirst position of the couch may relate to a distance between thereference position of the couch and the first position of the couch asreflected in the first set of imaging data. In some embodiments, thedistance between the reference position of the couch and the firstposition of the couch may be assessed in terms of or approximated by alength of a portion of the couch between the reference position and thefirst position of the couch. In some embodiments, the longer thedistance (e.g., the length of the portion of the couch) between thereference position and the first position is, the greater the rotationangle associated with the first position of the couch may be. Therotation angle associated with the first position may relate to adistance between the spatial basis function representation correspondingto the first position and the reference basis function representationcorresponding to the reference position. In some embodiments, thegreater the distance between the spatial basis function representationand the reference basis function representation is, the greater therotation angle associated with the first position may be.

In some embodiments, the rotation angle associated with a first positionmay be determined based on a distance (e.g., a length of a portion ofthe couch) between the reference position and the first positionreflected in the first set of imaging data, an offset in a verticaldirection of the first conformation at the first position from thereference conformation, and/or a distance in a horizontal directionbetween a reference position and the first position. As used herein, theoffset in a vertical direction may also be referred to as a deformationelement in a vertical direction of the first conformation at the firstpositon from the reference conformation. More descriptions fordetermining a rotation angle associated with a position of a couch maybe found elsewhere in the present disclosure. See for example, FIG. 8and FIG. 9 and the descriptions thereof.

In 606, the first set of imaging data may be adjusted based on thedisplacement field associated with the first set of imaging data withrespect to the reference conformation. Operation 606 may be performed bythe image correction module 530. In some embodiments, the first set ofimaging data may be adjusted by moving the plurality of spatial basisfunction representations based on the displacement field. For example, aspatial basis function representation may correspond to a rotationangle. A spatial basis function representation may be adjusted based ona rotation angle corresponding to the spatial basis functionrepresentation. In some embodiments, the adjustment may be performed,based on the displacement field, on the pixel or voxel basis withrespect to the first set of imaging data. In some embodiments, the firstset of imaging data affording to the sagittal view may correspond tosecond set of imaging data affording to an axial view. The first set ofimaging data may be adjusted by adjusting the second set of imaging dataaffording to the axial view based on the displacement field. Further,the adjustment may be performed on pixels or voxels with respect to thesecond set of imaging data based on the displacement field. The firstset of imaging data may be determined based on the adjusted second setof imaging data. In some embodiments, imaging data in the second set ofimaging data corresponding to the reference position of the couch doesnot need to be adjusted.

In 608, an image of the subject with respect to the referenceconformation may be obtained based on the adjusted first set of imagingdata. Operation 608 may be performed by the image correction module 530.In some embodiments, the image of the subject with respect to thereference conformation may be obtained by performing a negativetransformation on the adjusted first set of imaging data based on theplurality of spatial basis functions as described in 602. Further, theadjusted spatial basis function representations may be transformed intoone or more images of the subject. The imaging data adjusted based on adisplacement field associated with images in a view (e.g., in a sagittalview) may be used to provide adjusted images in another view (e.g., in acoronal view). The adjusted first set of imaging data may be used togenerate an adjusted 3D image. The adjusted first set of imaging datamay be used to generate one or more adjusted 2D image slices in one ormore planes, e.g., one or more sagittal planes, one or more coronalplanes, one or more axial planes, one or more same or different obliqueplanes. For instance, the adjusted first set of imaging data may be usedto generate a series of 2D image slices in different axial planes, or aseries of 2D image slices in different sagittal planes, or a series of2D image slices in different coronal planes, or one or more 2D imageslices in parallel or nonparallel oblique planes.

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations or modifications may be made under the teachings ofthe present disclosure. However, those variations and modifications donot depart from the scope of the present disclosure. For example,process 600 may include obtaining the first image affording a sagittalview corresponding to the first set of imaging data and transforming thefirst image into the first set of imaging data based on a plurality ofspatial basis functions. As another example, process 600 may furtherinclude obtaining a second set of imaging data affording a sagittal viewrelating to the subject and the couch and determining the referenceconformation based on the second set of imaging data. The couch mayinclude a plurality of second positions reflected in the second set ofimaging data as the reference conformation.

FIG. 7 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure.In some embodiments, one or more operations of process 700 illustratedin FIG. 7 may be implemented in the diagnostic and treatment system 100illustrated in FIG. 1 . For example, process 700 illustrated in FIG. 7may be stored in the storage 130 in the form of instructions, andinvoked and/or executed by the processing device 120 (e.g., theprocessor 310 of the computing device 300 as illustrated in FIG. 3 , theGPU 430 or CPU 440 of the mobile device 400 as illustrated in FIG. 4 ).With respect to 604, the reference conformation may correspond to thesecond conformation of the second couch, the first conformation maycorrespond to the first conformation of the first couch referred to inthe description of FIG. 7 , and the second stack of image slices areomitted.

In 702, a first image slice may be obtained. The first image slice mayafford a sagittal view relating to an ROI of a subject and a first couchsupporting the subject. The first couch may include a plurality of firstpositions reflected in the first image slice as a first conformation.Operation 702 may be performed by the image data acquisition module 510.In some embodiments, the first image slice may be obtained based on afirst set of imaging data. The first set of imaging data may be obtainedfrom the storage 130, the terminal(s) 140, the storage module 540, orany other external storage. In some embodiments, the first set ofimaging data may be acquired by scanning the subject supported on thesecond couch using a first device (e.g., the medical apparatus 110)including an imaging device. Exemplary imaging devices may include a CTdevice, a CBCT device, a PET device, a volume CT device, an MRI device,a SPECT device, etc. The first device may further include aninterventional medical device, for example, a radiation therapytreatment (RT) device, an ultrasound treatment device, a thermaltreatment device, a surgical intervention device, or the like, or acombination thereof.

In some embodiments, the first set of imaging data may be presented as afirst stack of image slices affording sagittal views, a first stack ofimage slices affording coronal views, a first stack of image slicesaffording axial views, spatial basis function representations, or acombination thereof. The first image slice may correspond to the firststack of image slices affording axial views relating to the ROI of thesubject and the first couch. An image slice of the first stack affordingan axial view may correspond to a first position of the first couch.

In some embodiments, the first conformation may be reflected in thefirst image slice affording the sagittal view as a first line. The firstimage slice may include a portion corresponding to the isocenter of thefirst device acquiring the first set of imaging data. For brevity, asused herein, an isocenter of a device (e.g., the imaging device 112) mayrefer to the isocenter of the physical device, or a portion of an imageslice or imaging data that corresponds to the isocenter of the physicaldevice.

In some embodiments, the first image slice affording the sagittal viewmay include a guiding image relating to the ROI of the subject. As usedherein, a guiding image may be used to guide the implementation of thetreatment plan of the subject. For example, the guiding image relatingto the ROI of the subject may be used to position the ROI. Thepositioned ROI may receive radiation according to the treatment plan.The guiding image may be taken during or before the radiation therapy(e.g., on the day of treatment, or hours before the treatment, orminutes before the treatment, or seconds before the treatment, or duringthe treatment).

In 704, a second image slice may be obtained. The second image slice mayafford a sagittal view relating to the ROI of the subject and a secondcouch supporting the subject. The second couch may include a pluralityof second positions reflected in the second image slice as a secondconformation. Operation 704 may be performed by the image dataacquisition module 510. A second position of the second couch maycorrespond to a first position of the first couch. As used herein, asecond position may be considered to correspond to a first position ifthe first position and the second position are located away from areference position by a same distance (e.g., P_(i) and Q_(i) asillustrated in FIG. 9 ). In some embodiments, the second conformationmay be reflected in the second image slice as a second line.

In some embodiments, the second image slice may be obtained based on asecond set of imaging data. In some embodiments, the second set ofimaging data may be obtained from the storage 130, the terminal(s) 140,the storage module 540, or any other external storage. In someembodiments, the second set of imaging data may be acquired by scanningthe subject supported on the second couch using a second device. Thesecond device may include a CT device, a CBCT device, a PET device, avolume CT device, an MRI device, a SPECT device, or the like, or acombination thereof.

In some embodiments, the second set of imaging data may be presented asa second stack of image slices affording sagittal views, a second stackof image slices affording coronal views, a second stack of image slicesaffording axial views, spatial basis function representations, or acombination thereof. The second image slice may correspond to the secondstack of image slices affording axial views relating to the ROI of thesubject and the second couch. An image slice of the second stackaffording an axial view may correspond to a second position of thesecond couch. The second image slice affording a sagittal view mayinclude a portion corresponding to the isocenter of the second deviceacquiring the second set of imaging data.

In some embodiments, the second image slice may include a planning imagerelating to the ROI of the subject. As used herein, a planning image maybe used to design a treatment plan of the subject. For example, theplanning image may be taken before the subject receives a radiationtherapy (e.g., days or weeks before). The planning image may be used toidentify a focus, a treatment target (e.g., the ROI of the subject), anorgan at risk, and the external contour of the subject, and thetreatment plan may be designed for the subject based on the planningimage.

In some embodiments, the first couch and the second couch may be thesame couch. For instance, the first set of imaging data and the secondset of imaging data may be acquired by scanning the subject using a sameimaging device including a couch for supporting the subject (e.g., asame CT scanner in a same IGRT device, a same imaging device 112 of thesame medical apparatus 110). In some embodiments, the first couch andthe second couch may be two different couches. For instance, the firstset of imaging data and the second set of imaging data may be acquiredby scanning the subject using different imaging devices having differentcouches for supporting the subject, e.g., a CT scanner in an IGRT deviceand a different CT scanner.

In 706, a displacement field associated with the first image slice maybe determined based on the first conformation and the secondconformation. Operation 706 may be performed by the displacementdetermination module 520. The displacement field may include a pluralityof displacement components. A displacement component may be associatedwith a first position. As used herein, a displacement component mayreflect a change of a position of the first couch reflected in the firstimage slice (e.g., the first conformation) with respect to the secondconformation. At least two displacement components of the plurality ofdisplacement components may be different. The displacement componentsmay be local, depending on their corresponding first positions of thefirst couch. The displacement component associated with the firstposition may include a distance from the first position to a correctedfirst position of the first couch with respect to the secondconformation and a direction from the first position to the correctedfirst position of the first couch with respect to the secondconformation reflected in the first image slice. In some embodiments, adistance between a first position and the reference position reflectedin the first image slice and a distance between an adjacent firstpositon and the reference position reflected in the reflected in thefirst image slice may be different. In some embodiments, these distancesmay change as a function of the first positions nonlinearly. See, e.g.,FIG. 9 . A displacement component associated with the reference positionmay equal 0. In other words, the distance between the reference positionand a corrected reference position of the first couch with respect tothe second conformation may equal 0. The first conformation may coincidewith the second conformation at the reference position. A distance fromthe first position to the corrected first position of the first couchwith respect to the second conformation may relate to the distancebetween a reference position and the first position reflected in thefirst image slice. In some embodiments, the distance between thereference position and the first position may be assessed in terms of orapproximated by a length of a portion of the first portion between thereference position and the first position. In some embodiments, thelonger the distance (e.g., the length of a portion of the first couch)between the reference position and the first position is, the greaterthe displacement component associated with the first position may be. Asused herein, the reference position of the second couch or the referenceposition of the first couch may refer to a second position of the secondcouch or a corresponding first position of the first couch that thefirst conformation at the reference position of the first couch is thesame as the second conformation of the second couch at the referenceposition. The reference position of the first couch or the referenceposition of the second couch may correspond to an intersection betweenthe first conformation and the second conformation. The firstconformation may coincide with the second conformation at the referenceposition. In some embodiments, the intersection between the firstconformation and the second conformation may be determined byregistering the first image slice and the second image slice. In someembodiments, the first image slice and the second image slice may beregistered based on, e.g., a characteristic feature appearing in bothimage slices. Exemplary characteristic features may correspond to acommon marker, a common feature, etc., of the subject and/or the firstcouch and the second couch. In some embodiments, the first image sliceand the second image slice may be registered based on the isocenter ofthe first device acquiring the first image slice and the isocenter ofthe second device acquiring the second image slice. The isocenter of thefirst device acquiring the first image slice and the isocenter of thesecond device may be coincident in the third image slice.

In some embodiments, the displacement field associated with the firstimage slice may be determined by determining each of the plurality ofdisplacement components corresponding to one first position of the firstcouch. A displacement component associated with a specific firstposition may be determined based on the first conformation reflected inthe first image slice and the second conformation reflected in thesecond image slice. In some embodiments, the first conformation and thesecond conformation may be illustrated in one image slice. In someembodiments, the displacement component associated with the specificfirst position may be determined based on a distance (e.g., a length ofa portion of the first couch) between the reference position and thespecific first position reflected in the first image slice. The lengthof the portion of the first couch between the reference position and thespecific first position may be determined based on a length of a sectionof the first conformation (i.e., the first line) between the referenceposition and the specific first position reflected in the first imageslice.

In some embodiments, a direction from a specific first position to thecorrected specific first position of the first couch with respect to thesecond conformation may be defined by a rotation angle associated withthe specific first position. The rotation angle associated with thespecific first position may relate to a distance (e.g., a length of aportion of the second couch) between the reference position to thespecific first position reflected in the second image slice. In someembodiments, the longer the distance (e.g., the length of a portion ofthe first couch) between the reference position to a specific firstposition is, the greater the rotation angle associated with the specificfirst position may be. In some embodiments, the rotation angleassociated with the specific first position may be determined based onthe distance (e.g., the length of the portion of the first couch)between the reference position to the specific first position, an offsetin a vertical direction of the first couch at the specific firstposition of the first conformation from the first conformation, and/or adistance in a horizontal direction between the reference position andthe specific first position. More descriptions for determining adisplacement component associated with a specific position may be foundin FIG. 8 and/or FIG. 9 .

In 708, the stack of third image slices may be adjusted based on thedisplacement field. Operation 708 may be performed by the imagecorrection module 530. In some embodiments, the stack of third imageslices may be adjusted by correcting each third image slice of the stackbased on a displacement component associated with a first positioncorresponding to the each image slice of the first stack affording anaxial view. Further, the each third image slice affording an axial viewmay be corrected by moving all pixels in the each image third slice ofthe stack based on the corresponding displacement component. In someembodiments, the stack of third image slices or the first image slicemay correspond to a volume image (e.g., a three-dimension image)relating to the ROI and the first couch. The stack of third image slicesmay be adjusted by moving all voxels in the volume image based on thedisplacement field. In some embodiments, the stack of third image slicesmay correspond to imaging data relating to the ROI of the subject andthe first couch. The imaging data may be presented as a plurality ofspatial basis function representations as descried in connection withFIG. 6 . The stack of third image slices may be adjusted by moving theplurality of spatial basis function representations based on thedisplacement field. Then, the adjusted stack of third image slices maybe obtained based on the adjusted imaging data (i.e., the adjustedplurality of spatial basis function representations). The imaging dataadjusted based on a displacement field associated with images in a view(e.g., in a sagittal view) may be used to provide adjusted images inanother view (e.g., in a coronal view).

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations or modifications may be made under the teachings ofthe present disclosure. However, those variations and modifications donot depart from the scope of the present disclosure. For example,operation 702 may be omitted. The first conformation may be designatedas a reference conformation as described in FIG. 6 . As another example,operations 702 and 704 may be performed simultaneously. In someembodiments, operation 708 may be omitted. For example, a third imageslice in the stack of third image slices corresponding to the referenceposition of the first couch does not need to be adjusted based on adisplacement component associated with the reference position.

FIG. 8 is a flowchart illustrating an exemplary process for determininga displacement field associated with a second image slice according tosome embodiments of the present disclosure. In some embodiments, one ormore operations of process 800 illustrated in FIG. 8 may be implementedin the diagnostic and treatment system 100 illustrated in FIG. 1 . Forexample, process 800 illustrated in FIG. 8 may be stored in the storage130 in the form of instructions, and invoked and/or executed by theprocessing device 120 (e.g., the processor 310 of the computing device300 as illustrated in FIG. 3 , the GPU 430 or CPU 440 of the mobiledevice 400 as illustrated in FIG. 4 ). Operations 604 and 706 may beperformed according to process 800 as illustrated in FIG. 8 . Withrespect to 604, the reference conformation may correspond to the secondconformation of the second couch, the first conformation may correspondto the first conformation of the first couch referred to in thedescription of FIG. 8 , and the second image slice is omitted.

In 802, a reference position of a second couch reflected in a secondimage slice or a first couch reflected in a first image slice may bedetermined. Operation 802 may be performed by the displacementdetermination module 520. The first image slice relating to an ROI of asubject and the first couch supporting the subject may be obtained asdescribed in connection with operation 702. The second image slicerelating to the ROI of the subject and the second couch may be obtainedas described in connection with operation 704. The first image slice andthe second image slice may each afford a sagittal view. The first couchmay include a plurality of first positions reflected in the first imageslice as a first conformation. The second couch may include a pluralityof second positions reflected in the second image slice as a secondconformation. In some embodiments, the first image slice may correspondto a first stack of image slices relating to the ROI of the subject andthe first couch affording axial views. The second image slice maycorrespond to a second stack of image slices relating to the ROI of thesubject and the second couch affording the axial views. Each of thefirst positions may correspond to one image slice in the first stack.Each of the second positions may correspond to one image slice in thesecond stack. A second position of the second couch may correspond to afirst position of the first couch.

The reference position of the second couch reflected in the second imageslice and/or the first couch reflected in the first image slice may bedetermined based on the second conformation and the first conformationreflected in the second image slice and the first image slice,respectively. In some embodiments, the first conformation of the firstcouch may be segmented and/or identified from the first image slice as afirst line (e.g., line 920 as shown in FIG. 9 ). A first position of thefirst couch may be reflected in the first image slice as a first point(e.g., point P₁ point P_(i), point P_(i+1), etc., as shown in FIG. 9 ).The second conformation of the second couch may be segmented and/oridentified from the second image slice as a second line (e.g., line 910as shown in FIG. 9 ). A second position of the second couch may bereflected in the second image slice as a second point (e.g., point Q₁,point Q_(i), point Q_(i+1), etc., as shown in FIG. 9 ). The referencepositon of the second couch reflected in the second image slice or thefirst couch reflected in the first image slice may correspond to areference point (e.g., point P_(r) as shown in FIG. 9 ).

In some embodiments, the first image slice including the first line andthe second image slice including the second line may be registered toform a third image slice (e.g., the image shown in FIG. 9 ) includingthe first line and the second line. For instance, the first positions onthe first line corresponding to the first conformation may relate to thedistances of the first couch from the floor at the first positions, andthe second positions on the first line corresponding to the secondconformation may relate to the distances of the second couch from thefloor at the second positions; the second line may be reproduced in thefirst image slice based on the distances of the second couch from thefloor at the second positions. As another example, the first image sliceand the second image slice may be registered based on, e.g., acharacteristic feature appearing in both image slices. Exemplarycharacteristic features may correspond to a common marker, a commonfeature, etc. As a further example, the first image slice and the secondimage slice may be registered based on an isocenter of a first deviceacquiring the first image slice and an isocenter of a second deviceacquiring the second image slice. The isocenter of the first deviceacquiring the first image slice and the isocenter of the second devicemay be coincident in the third image slice. An intersection point of thefirst line and the second line may be designated as the reference point(also referred to as the reference position of the second couchreflected in the second image slice or the first couch reflected in thefirst image slice).

In 804, a length of a portion of the first couch between the referenceposition and a first position reflected in the first image slice may bedetermined. Operation 804 may be performed by the displacementdetermination module 520. In some embodiments, the length (also referredto as a first length) of the portion of the first couch from thereference position to the first position reflected in the first imageslice may be determined based on a length of a section of the first line(i.e., the first conformation reflected in the first image slice) fromthe reference point (e.g., point P_(r) as shown in FIG. 9 ) to a firstpoint (e.g., point P₁, point P₂, point P_(i), point P_(i+1), pointP_(n), etc., as shown in FIG. 9 ).

In some embodiments, a section of the first line from the referencepoint (e.g., point P_(r) as shown in FIG. 9 ) to a first point (e.g.,point P₁, point P₂, point P_(i), point P_(i+1), point P_(n), etc., asshown in FIG. 9 ) may be considered as a straight line connecting thereference point and the first point. The length of the section of thefirst line from the reference point (e.g., point P_(r) as shown in FIG.9 ) to the first point (e.g., point P₁, point P₂, point P_(i), pointP_(i+1), point P_(n), etc., as shown in FIG. 9 ) may be equal to adistance between the reference point (e.g., point P_(r) as shown in FIG.9 ) and the first point (e.g., point P₁, point P₂, point P_(i), pointP_(i+1), point P_(n), etc., as shown in FIG. 9 ). The reference pointmay correspond to the reference position. A first point may correspondto a first position of the first couch. The distance between thereference point and the first point may be determined according to,e.g., a trigonometric relationship. For instance, the distance betweenthe reference point and the first point may be determined as thehypotenuse of a right-angled triangle based on a first distance in ahorizontal direction between the reference point and the first point anda second distance in a vertical direction between the reference pointand the first point.

In some embodiments, the first distance in the horizontal directionbetween the reference point and the first point may be determined basedon the interval between an image slice of the first stack correspondingto the reference position (e.g., position Z_(r) as shown in FIG. 9 ) andan image slice of the first stack corresponding to the second position(e.g., position Z_(i) as shown in FIG. 9 ). If the slice intervalsbetween adjacent image slices are constant, the first distance in thehorizontal direction may be determined based on the number of slicesbetween the reference point and the second point and the sliceintervals.

In some embodiments, the second distance (e.g., distance Q_(r)P_(i) asshown in FIG. 9 ) in the vertical direction between the reference pointand the second point may be also referred to as an offset in thevertical direction of the first conformation at the first position fromthe second conformation at the corresponding second position. The seconddistance (e.g., distance Q_(r)P_(i) as shown in FIG. 9 ) in the verticaldirection may be determined based on a distance (e.g., distanceQ_(i)P_(i) as shown in FIG. 9 ) between the first line and the secondline at the first position, if the second line (line 910) is ahorizontal straight line as illustrated in FIG. 9 . For instance, asillustrated in FIG. 9 , the second distance may be the differencebetween the distance Y_(i)P_(i) in the vertical direction between thefirst point P_(i) and a based line 930 and the distance Y_(i)Q_(i) inthe vertical direction between a corresponding point Q_(i) on the secondline to the line 930. As used herein, the base line may be a horizontalstraight line passing the isocenter of a first device acquiring thefirst image slice.

In some embodiments, the first length of the portion of the first couchfrom the reference position to the first position reflected in the firstimage slice may be determined based on multiple section lengths ofmultiple portions of the first couch reflected in the first image slice.A section length may correspond to a pair of adjacent first positions ofthe first couch between the reference position and the first positionreflected in the first image slice. A section length of a portion of thefirst couch between adjacent first positions may be determined based ona distance in a horizontal direction between the adjacent firstpositions (i.e., the slice interval) and an offset in the verticaldirection of the first conformation at the adjacent first positions. Theoffset in the vertical direction of the first conformation at theadjacent first positions may be determined similarly to that describedin connection with the determination of Q_(i)P_(i), the description ofwhich is not repeated. The first length of the portion of the firstcouch from the reference position to the first position reflected in thefirst image slice may be equal to a sum of the multiple section lengths.

In 806, a displacement component corresponding to the first positionbased on the first length of the portion of the first couch from thereference position to the first position may be determined. Operation806 may be performed by the displacement determination module 520.

The displacement component associated with the first position mayinclude a distance between the first position and a corrected firstposition of the first couch with respect to the second conformation anda direction from the first position to the corrected first position ofthe first couch with respect to the second conformation. In someembodiments, a distance between a first position and the referenceposition reflected in the first image slice and a distance between anadjacent first positon and the reference position reflected in thereflected in the first image slice may be different. In someembodiments, these distances may change as a function of the firstpositions nonlinearly. See, e.g., FIG. 9 . In some embodiments, thedisplacement component corresponding to the reference position may equal0. The distance between the reference position and a corrected referenceposition of the first couch with respect to the second conformation maybe 0. The first conformation may coincide with the second conformationat the reference position. In some embodiments, the corrected firstposition of the first couch with respect to the second conformation maybe determined in the first image slice based on the first length. Asused herein, the corrected first position may refer to an ideal positionof the first position in the first image slice after deformationcorrection of the first conformation with respect to the secondconformation. The corrected first position of the first couch may bedetermined based on a second length of a portion of the first couch fromthe reference position to the corrected first position of the firstcouch with respect to the second conformation of the second couch. Thesecond length may be determined based on the first length. In someembodiments, the second length may be equal to the first length.

In some embodiments, the second length may relate to an elasticextension of the portion of the first couch from the reference positionto the first position. Further, the second length may be determinedbased on a difference between the elastic extension and the first lengthof the portion of the first couch between the reference position and thefirst position. In some embodiment, the elastic extension of the portionof the first couch between the reference position and the first positionmay be determined by simulating a stress distribution in the first couchwith a load with the same weight of the subject using a numerical method(e.g., finite element method). The displacement component may then bedetermined based on the first position and the corrected first positionreflected in the first image slice. For example, the first position maybe reflected in the first image slice as the first point (e.g., pointP_(i), point P_(i+1), point P_(n), etc., as shown in FIG. 9 ). Thecorrected first position may be reflected in the first image slice as acorrected first point (e.g., point S_(i), point S_(i+1), point S_(n),etc., as shown in FIG. 9 ). The displacement component may be determinedbased on a mapping from the first point (e.g., point P_(i), pointP_(i+1), point P_(n), etc., as shown in FIG. 9 ) to the corrected firstpoint (e.g., point S_(i), point S_(i+1), point S_(n), etc., as shown inFIG. 9 ). Further, the displacement component may be a vector (e.g.,P_(i)S_(i), P_(i+1)S_(i+1), P_(i+1)S_(i+1), etc., as shown in FIG. 9 )from the first point to the corrected first point.

In some embodiments, the direction from the first position to thecorrected first position of the first couch with respect to the secondconformation may be defined by a rotation angle associated with thefirst positon. Two different first positions of the first couch maycorrespond to different rotation angles from the two first positions totwo corrected first position of the first couch respectively withrespect to the second conformation Then, the displacement component maybe defined by a rotation angle and/or the offset in the verticaldirection of the first conformation at the first positon from the secondconformation. In some embodiments, the rotation angle associated withthe reference positon may equal 0. In some embodiments, a rotation angleassociated with the first position may be determined based on the firstlength, the first distance in the horizontal direction, and/or thesecond distance in the vertical direction. For example, the rotationangle associated with the first position may be determined based on thefirst length and the first distance in the horizontal direction using aninverse cosine function. As another example, the rotation angleassociated with the first position may be determined based on the firstlength and the second distance in the vertical direction using aninverse sine function. As still an example, the rotation angleassociated with the first position may be determined based on the firstdistance in the horizontal direction and the second distance in thevertical direction using an inverse tangent function or cotangentfunction. In some embodiments, the rotation angle associated with thefirst position may be an angle (e.g., angle θ_(i), angel θ_(i+1), angleθ_(n), etc., as shown in FIG. 9 ) between the displacement component(e.g., vector P_(i)S_(i), vector P_(i+1)S_(i+1), vector P_(n)S_(n),etc., as shown in FIG. 9 ) and the second distance (e.g., distanceP_(i)Q_(j), distance P_(i+1)Q_(i+1), distance P_(n)Q_(n), etc., as shownin FIG. 9 ) in the vertical direction. The second distance in thevertical direction may be a component in the vertical direction of thedisplacement component. Then, the displacement component may bedetermined based on the rotation angle associated with the firstposition and the second distance in the vertical direction. Moredescriptions for determining the rotation angle may be found elsewherein the present disclosure (e.g., FIG. 9 , and the descriptions thereof).

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations or modifications may be made under the teachings ofthe present disclosure. However, those variations and modifications donot depart from the scope of the present disclosure. For example,operation 804 may be divided into multiple operations, includingdetermining a first distance in a horizontal direction from a referenceposition to a first position reflected in the first image slice,determining an offset in the vertical direction of the first couch atthe first position with respect to the reference position, anddetermining the length of a portion of the second couch from thereference position to the first position reflected in the first imageslice based on the first distance and the offset.

FIG. 9 is a schematic diagram illustrating an example for determining adisplacement component according to some embodiments of the presentdisclosure. In some embodiments, the image shown in FIG. 9 may beobtained by registering a first image slice relating to a subject and afirst couch and a second image slice relating to the subject and asecond couch. The first image slice and the second image slice mayafford a sagittal view. In some embodiments, the image shown in FIG. 9may be obtained by adding a reference conformation to a first imageslice relating to the subject and a first couch. In some embodiments,the line 910 may represent a second conformation of a second couchreflected in the image or the reference conformation. For illustrationpurposes, FIG. 9 is described with reference to the referenceconformation. A line 920 represents a first conformation of a firstcouch reflected in the image. A line 930 represents a base linecorresponding to a line passing the isocenter of the device acquiringthe first image slice or second image slice. The first couch may includea plurality of first positions reflected in the image as multiple firstpoints on the line 920 (e.g., point P₁, point P₂, point P_(i), pointP_(i+1), point P_(n), etc.). The reference conformation of the firstcouch may include a plurality of second positions reflected in the imageas multiple second points on the line 910 (e.g., point Q₁, point Q₂,point Q_(i), point Q_(i+1), point Q_(n), etc.). Point P_(r) represents areference position of the first couch. Point P_(r) is an intersection ofthe line 910 and the line 920. A second position (e.g., point Q₁, pointQ₂, point Q_(i), point Q_(i+1), point Q_(n), etc.) and the correspondingfirst position (e.g., point P₁, point P₂, point P_(i), point P_(i+1),point P_(n), etc.) correspond to the same image slice number affordingan axial view corresponding to the first image slice.

A length of a portion of the first couch between a first position P_(i)and the reference position P_(r) reflected in the image may bedetermined based on a length (also referred to as length L_(ir)) of asection of the first line 920 between point P_(i) corresponding to thefirst position Z_(i) and reference point P_(r). The length of thesection of the line 920 between point P_(i) and reference point P_(r)may be determined according to Equation (1):

$\begin{matrix}{L_{ir} = \left\{ {\begin{matrix}{{L_{i - {1r}} + \sqrt{{❘{Z_{i} - Z_{i - 1}}❘}^{2} + {❘{Y_{i} - Y_{i - 1}}❘}^{2}}},} & {r < i \leq N} \\{0,} & {i = r} \\{{l_{i + {1r}} + \sqrt{{❘{Z_{i + 1} - Z_{i}}❘}^{2} + {❘{Y_{i + 1} - Y_{i}}❘}^{2}}},} & {1 \leq i < r}\end{matrix},} \right.} & (1)\end{matrix}$

where Li, denotes the length of the section of the second line 1120between point P_(i) and reference point P_(r), |Z_(i)−Z_(i−1)| or|Z_(i+1)−Z_(i)| denotes a distance in the horizontal direction betweenadjacent first positions reflected in the image slice, Y_(i) denotes adistance between point P_(r) and line 930, and |Y_(i)−Y_(i−1)| or|Y_(i+1)−Y_(i)| denotes an offset difference in the vertical directionof the first conformation between adjacent first positions reflected inthe image slice. The offset difference in the vertical direction mayalso referred to as a deformation difference in the vertical directionof the first couch between adjacent first positions reflected in theimage slice. Distances in the horizontal direction between adjacentfirst positions reflected in the image are equal to a slice intervalp_(d) between adjacent image slices affording axial views, such as|Z_(N)−Z_(N−1)|=|Z_(N−1)−Z_(N−2)|= . . . =|Z₂−Z₁|=p_(d).

In some embodiments, a length of a portion of the first couch between afirst position P_(i) and the reference position P_(r) reflected in theimage may be determined based on a distance between point P_(i) andpoint P_(r). The distance between point P_(i) and point P_(r) may bedetermined according to Equation (2) below:

P _(r) P _(i)=√{square root over (|Z _(i) −Z _(r)|² +|Y _(i) −Y_(r)|²)},  (2)

where P_(r)P_(i) denotes the distance between point P_(i) and pointP_(r).

A displacement component P_(i)S_(i) associated with the first positionP_(i) may be determined based on the length of the portion of the firstcouch between the first position P_(i) and the reference position P_(r)reflected in the image slice. A corrected first position of the firstcouch may be determined based on the length of the portion of the firstcouch between the first position P_(i) and the reference position P_(r)reflected in the image slice and the reference conformation. Thecorrected first position is reflected in the image slice as point S_(i)on line 910. A length of a section of line 910 between point P_(r) andpoint S_(i) (also referred to as a distance between point P_(r) andpoint S_(i)) corresponding to the corrected first position may bedetermined based on the length of the section of line 920 between pointP_(r) and point P_(i) (also referred to as a distance between pointP_(r) and point P_(i)) corresponding to the first position. In someembodiments, a distance between a first point (e.g., the first pointP_(i)) and the reference point P_(r) reflected in the image slice and adistance between an adjacent first point (e.g., the first point P_(i+1))and the reference point P_(r) reflected in the image slice may bedifferent. In some embodiments, these distances may change as a functionof the first positions nonlinearly. See, e.g., FIG. 9 . As used herein,an adjacent first point may correspond to an image slice in an axialview adjacent from the image slice including the first point in theaxial view. The displacement component may be denoted as a vectorP_(i)S_(i). The displacement component associated with a first position(e.g., the first point P_(i)) may include a distance from the firstpoint (e.g., the first point P_(i)) to a corrected first point (e.g.,point S_(i)) and a direction from the first position (e.g., the firstpoint P_(i)) to the corrected first position (e.g., point S_(i)).

In some embodiments, the direction of the displacement componentassociated with the first position P_(i) may be defined by a rotationangle θ_(i). Rotation angle θ_(i) associated with the first positionP_(i) may be determined according to one of Equations (3)-(5) below:

$\begin{matrix}{{\theta_{i} = {\tan^{- 1}\left( \frac{❘{Y_{i} - Y_{r}}❘}{\left. {❘{Z_{i} - Z_{r}}❘} \right)} \right)}},} & (3)\end{matrix}$ $\begin{matrix}{{\theta_{i} = {\cos^{- 1}\left( \frac{❘{Z_{i} - Z_{r}}❘}{L_{ir}} \right)}},} & (4)\end{matrix}$ $\begin{matrix}{\theta_{i} = {{\sin^{- 1}\left( \frac{❘{Y_{i} - Y_{r}}❘}{L_{ir}} \right)}.}} & (5)\end{matrix}$

A direction (e.g., rotation angle θ_(i)) of a displacement componentassociated with a first position (e.g., the first position P_(i)) may bedifferent from a direction (e.g., rotation angle θ_(i+1)) of adisplacement component associated with other first positions (e.g., thefirst position P_(i+1), the first position P_(n), etc.). Thedisplacement component associated with the reference position (e.g., thereference point P_(r)) may equal 0. In other words, the distance betweena corrected reference point (i.e., the reference point P_(r)) and thereference point (i.e., the reference point P_(r)) reflected in the imageslice may equal 0. A rotation angle of the displacement componentassociated with the reference position (i.e., the reference point P_(r))may equal 0.

FIG. 10 is a flowchart illustrating an exemplary process for correctingan image slice according to some embodiments of the present disclosure.In some embodiments, one or more operations of process 1000 illustratedin FIG. 10 may be implemented in the diagnostic and treatment system 100illustrated in FIG. 1 . For example, process 900 illustrated in FIG. 10may be stored in the storage 130 in the form of instructions, andinvoked and/or executed by the processing device 120 (e.g., theprocessor 310 of the computing device 300 as illustrated in FIG. 3 , theGPU 430 or CPU 440 of the mobile device 400 as illustrated in FIG. 4 ).With respect to 604, the reference conformation may correspond to thesecond conformation of the second couch, the first conformation maycorrespond to the first conformation of the first couch referred to inthe description of FIG. 10 , and the second stack of image slices areomitted.

In 1002, a first stack of image slices may be obtained. The first stackof image slices may afford axial views relating to the ROI of thesubject and a second couch supporting the subject. The first couch mayhave a plurality of first positions reflected in the first stack ofimage slices as a first conformation. Operation 1002 may be performed bythe image data acquisition module 510. In some embodiments, the firststack of image slices may be obtained from the storage 130, theterminal(s) 140, the storage module 540, or any other external storage.In some embodiments, the first stack of image slices may be acquired byscanning the subject supported on the first couch using a first device.The first device may include a CT device, a CBCT device, a PET device, avolume CT device, an MRI device, a SPECT device, or the like, or acombination thereof.

The first stack of image slices affording axial views may correspond toa first image slice affording a sagittal view relating to the ROI of thesubject and the first couch as described in connection with operation702. An image slice of the first stack affording an axial view maycorrespond to a first position of the first couch.

In 1004, a second stack of image slices may be obtained. The secondstack of image slice may afford the axial views relating to the ROI ofthe subject and a second couch supporting the subject. The second couchmay have a plurality of second positions reflected in the second stackof image slices as a second conformation. Operation 1004 may beperformed by the image data acquisition module 510. In some embodiments,the second stack of image slices may be obtained from the storage 130,the terminal(s) 140, the storage module 540, or any other externalstorage. In some embodiments, the second stack of image slices may beacquired by scanning the ROI of the subject supported on the secondcouch using a second device. In some embodiments, the second device mayinclude a CT device, a CBCT device, a PET device, a volume CT device, anMRI device, a SPECT device, or the like, or a combination thereof.

The second stack of image slices affording axial views may correspond toa second image slice affording a sagittal view relating to the ROI ofthe subject and the second couch as described in connection withoperation 704. An image slice of the second stack affording an axialview may correspond to a second position of the second couch. A secondposition of the plurality of second positions may correspond to a firstposition of the plurality of first positions. An image slice of thesecond stack may correspond to an image slice of the first stack.

In 1006, a displacement field associated with the first stack of imageslices may be determined based on the first conformation and the secondconformation. Operation 1006 may be performed by the displacementdetermination module 520. The displacement field may include a pluralityof displacement components. A displacement component may be associatedwith a first position. An image slice of the first stack may correspondto a displacement component. In some embodiments, the displacement fieldassociated with the first stack of image slices may be determined bydetermining each of the plurality of displacement componentscorresponding to one image slice of the first stack. A displacementcomponent corresponding to an image slice of the first stack may bedetermined based on the first conformation at a first position reflectedin the image slice of the first stack and the second conformation at acorresponding second position reflected in a corresponding image sliceof the second stack.

The displacement component associated with a first position may includea distance between the first position and a corrected first position ofthe first couch with respect to the second conformation and a directionfrom the first position to the corrected first position of the firstcouch with respect to the second conformation reflected in the firststack of image slices. In some embodiments, a distance between a firstposition and the reference position reflected in the first stack ofimage slices and a distance between an adjacent first positon and thereference position reflected in the reflected in the first stack ofimage slices may be different. In some embodiments, these distances maychange as a function of the first positions nonlinearly. See, e.g., FIG.9 . A displacement component associated with the reference position mayequal 0. In other words, the distance between the reference position anda corrected reference position of the first couch with respect to thesecond conformation may equal 0. The first conformation may coincidewith the second conformation at the reference position. In someembodiments, the distance between the first position and a correctedfirst position of the first couch with respect to the secondconformation may be determined based on a distance (e.g., a length of aportion of the first couch) reflected in the first stack of image slicesbetween a reference position and a specific first position correspondingto the image slice. The reference position of the first couch may bedetermined as descried elsewhere in the present disclosure (e.g., FIGS.6-9 , and the descriptions thereof). In some embodiments, the length ofthe portion of the first couch between the reference position and thespecific first position may be determined based on a first distance in ahorizontal direction and a second distance in a vertical directionbetween the reference position and the specific first position reflectedin the first stack of image slices. The first distance in the horizontaldirection may be determined based on an interval between an image sliceof the first stack corresponding to the reference position and an imageslice of the first stack corresponding to the specific first position.The second distance in the vertical direction may also referred to as anoffset of the first conformation at the specific first position from thesecond conformation at a second position corresponding to the specificfirst position. The second distance in the vertical direction may bedetermined based on the first conformation reflected in the image sliceof the first stack corresponding to the specific first position and thesecond conformation reflected in a corresponding image slice of thesecond stack.

In some embodiments, the direction from the first position to thecorrected first position of the first couch with respect to the secondconformation may be defined by a rotation angle associated with theimage slice of the first stack. The rotation angle associated with theimage slice of the first stack may relate to a distance (e.g., a lengthof a portion of the first couch) between the reference position to thespecific first position reflected in the image slice of the first stack.The longer a length of a portion of the first couch between thereference position to a specific first position is, the greater therotation angle associated with the specific first position may be. Insome embodiments, the rotation angle associated with the specific firstposition may be determined based on the length of the portion of thefirst couch between the reference position to the specific firstposition, an offset in a vertical direction of the first couch at thespecific first position of the first conformation with respect to thesecond conformation, and/or a distance in a horizontal direction betweenthe reference position and the specific first position. Moredescriptions for determining a displacement component associated with aspecific position may be found in FIG. 8 and/or FIG. 9 .

In 1008, the first stack of image slices may be adjusted based on thedisplacement field. Operation 1008 may be performed by the imagecorrection module 530. In some embodiments, the first stack of imageslices may be adjusted by moving all pixels in at least one image slicein the first stack based on a corresponding displacement component. Insome embodiments, the first stack of image slices may correspond to avolume image (e.g., a three-dimension image) relating to the ROI. Thefirst stack of image slices may be adjusted by moving all voxels in thevolume image corresponding to the first stack of image slices based onthe displacement field. In some embodiments, the first stack of imagesmay correspond to imaging data relating to the ROI. The imaging datarelating to the ROI may be represented by spatial basis functionrepresentations. The imaging data relating to the ROI may be adjusted byadjusting the spatial basis function representations. Then, the adjustedfirst stack of image slices may be obtained based on the adjustedimaging data.

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations or modifications may be made under the teachings ofthe present disclosure. However, those variations and modifications donot depart from the scope of the present disclosure. For example,operation 1002 may be omitted. As another example, operations 1002 and1004 may be performed simultaneously. In some embodiments, operation1008 may be omitted. For example, an image slice in the first stackcorresponding to the reference position of the first couch does not needto be adjusted based on a displacement component associated with thereference position.

Examples

The following examples are provided for illustration purposes, and notintended to limit the scope of the present disclosure.

FIGS. 11A-11C are images affording sagittal views relating to anexemplary phantom and a couch supporting the phantom according to someembodiments of the present disclosure. A first image shown in FIG. 11Arelates to a phantom with negligible weight and a couch supporting thephantom. A second image shown in FIG. 11B relates to the phantom withweight of 100 kilograms and the couch supporting the phantom. Adisplacement field including a plurality of displacement components asdescribed elsewhere in the present disclosure is shown in FIG. 11B aswhite arrows. More descriptions of the white arrows may be found in FIG.12B. The third image shown in FIG. 11C was obtained by correcting thesecond image based on the displacement field in the second image.

FIGS. 12A-12C are images relating to the same locally amplified regionin FIGS. 11A-11C according to some embodiments of the presentdisclosure. As shown in FIG. 12B, white arrows denote a displacementfield. The displacement field includes a plurality of local displacementcomponents as described elsewhere in the present disclosure. Each of theplurality of displacement components is denoted by a white arrow. Thedisplacement components correspond to multiple positions of the couch. Aline 1220 in FIG. 12B or in FIG. 12C denotes a reference axial viewcorresponding to a reference position of the couch as describedelsewhere in the present disclosure. The displacement componentcorresponding to a position of the couch far from the reference axialview is greater than that corresponding to a position of the couch closeto the reference axial view.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure, and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Further, it will be appreciated by one skilled in the art, aspects ofthe present disclosure may be illustrated and described herein in any ofa number of patentable classes or context including any new and usefulprocess, machine, manufacture, or composition of matter, or any new anduseful improvement thereof. Accordingly, aspects of the presentdisclosure may be implemented entirely hardware, entirely software(including firmware, resident software, micro-code, etc.) or combiningsoftware and hardware implementation that may all generally be referredto herein as a “unit,” “module,” or “system.” Furthermore, aspects ofthe present disclosure may take the form of a computer program productembodied in one or more computer readable media having computer readableprogram code embodied thereon.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including electro-magnetic, optical, or thelike, or any suitable combination thereof. A computer readable signalmedium may be any computer readable medium that is not a computerreadable storage medium and that may communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device. Program code embodied on acomputer readable signal medium may be transmitted using any appropriatemedium, including wireless, wireline, optical fiber cable, RF, or thelike, or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB. NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2103, Perl, COBOL2102, PHP, ABAP, dynamic programming languages such as Python, Ruby andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose, and that the appendedclaims are not limited to the disclosed embodiments, but, on thecontrary, are intended to cover modifications and equivalentarrangements that are within the spirit and scope of the disclosedembodiments. For example, although the implementation of variouscomponents described above may be embodied in a hardware device, it mayalso be implemented as a software only solution, for example, aninstallation on an existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure aiding in theunderstanding of one or more of the various inventive embodiments. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, inventive embodiments liein less than all features of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities or propertiesused to describe and claim certain embodiments of the application are tobe understood as being modified in some instances by the term “about,”“approximate,” or “substantially.” For example, “about,” “approximate,”or “substantially” may indicate ±20% variation of the value itdescribes, unless otherwise stated. Accordingly, in some embodiments,the numerical parameters set forth in the written description andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by a particular embodiment. Insome embodiments, the numerical parameters should be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of some embodiments of the application areapproximations, the numerical values set forth in the specific examplesare reported as precisely as practicable.

Each of the patents, patent applications, publications of patentapplications, and other material, such as articles, books,specifications, publications, documents, things, and/or the like,referenced herein is hereby incorporated herein by this reference in itsentirety for all purposes, excepting any prosecution file historyassociated with same, any of same that is inconsistent with or inconflict with the present document, or any of same that may have alimiting affect as to the broadest scope of the claims now or laterassociated with the present document. By way of example, should there beany inconsistency or conflict between the description, definition,and/or the use of a term associated with any of the incorporatedmaterial and that associated with the present document, the description,definition, and/or the use of the term in the present document shallprevail.

In closing, it is to be understood that the embodiments of theapplication disclosed herein are illustrative of the principles of theembodiments of the application. Other modifications that may be employedmay be within the scope of the application. Thus, by way of example, butnot of limitation, alternative configurations of the embodiments of theapplication may be utilized in accordance with the teachings herein.Accordingly, embodiments of the present application are not limited tothat precisely as shown and described.

1-20. (canceled)
 21. A method implemented on a computing device havingat least one processor and at least one computer-readable storagemedium, the method comprising: obtaining a first set of imaging datarelating to a subject and a first couch supporting the subject, thefirst couch having a plurality of first positions reflected in the firstset of imaging data as a first conformation; determining an intersectionbetween a reference conformation and the first conformation; anddetermining, based on the intersection between the referenceconformation and the first conformation, the first conformation, and thereference conformation, a displacement field associated with the firstset of imaging data with respect to the reference conformation, thedisplacement field including a plurality of displacement componentscorresponding to the plurality of first positions.
 22. The method ofclaim 21, wherein the determining, based on the intersection between thereference conformation and the first conformation, the firstconformation, and the reference conformation, a displacement fieldassociated with the first set of imaging data with respect to thereference conformation includes: for one first position of the firstcouch, determining a corrected first point on the reference conformationcorresponding to a first point of the first set of imaging data on thefirst conformation based on the intersection, the first pointcorresponding to the one first position of the first couch; anddetermining a displacement component associated with the first point,wherein the displacement component of the first point is determined as avector from the first point to the corrected first point.
 23. The methodof claim 22, wherein a first distance between the corrected first pointand the intersection equals to a second distance between the first pointand the intersection.
 24. The method of claim 22, wherein thedisplacement component of the first point includes a third distance fromthe first point to the corrected first point, and a direction from thefirst point to the corrected first point.
 25. The method of claim 22,wherein distances between various first points and the intersectionchange as a function of corresponding first positions nonlinearly. 26.The method of claim 21, further comprising: adjusting, based on thedisplacement field, the first set of imaging data with respect to thereference conformation; and obtaining, based on the adjusted first setof imaging data, an image of the subject with respect to the referenceconformation.
 27. The method of claim 26, wherein the adjusting, basedon the displacement field, the first set of imaging data with respect tothe reference conformation includes: adjusting imaging data in an axialview corresponding to the first point in a sagittal view based on thedisplacement component corresponding to the first point.
 28. The methodof claim 27, further comprising: generating an adjusted 3D image sliceor an adjusted 2D image slice in a view other than the axial view basedon the adjusted imaging data.
 29. The method of claim 26, wherein theadjusting, based on the displacement field, the first set of imagingdata with respect to the reference conformation includes: moving, basedon the displacement field, spatial basis function representationscorresponding to the first set of imaging data.
 30. The method of claim21, wherein the displacement field includes a plurality of rotationangles, and the plurality of rotation angles relate to spatial basisfunction representations corresponding to the first set of imaging data.31. The method of claim 30, further comprising: determining a referenceposition of the first couch reflected in the first set of imaging data,the first conformation of the first couch coinciding with the referenceconformation at the reference position, the reference positioncorresponding to a reference spatial basis function representation. 32.The method of claim 21, wherein the reference conformation includes astraight horizontal line.
 33. The method of claim 21, wherein thereference conformation corresponds to a plurality of second positionsreflected in a second set of imaging data.
 34. The method of claim 33,wherein the second set of imaging data afford a sagittal view relatingto the subject and a second couch supporting the subject, and theplurality of second positions correspond to the second couch.
 35. Amethod implemented on a computing device having at least one processorand at least one computer-readable storage medium, the methodcomprising: obtaining a stack of image slices affording axial viewsrelating to a subject or an ROI of the subject and a first couchsupporting the subject, the first couch having a plurality of firstpositions reflected in the stack of image slices as a firstconformation; determining an intersection between a referenceconformation and the first conformation; determining, based on theintersection between the reference conformation and the firstconformation, the first conformation, and the reference conformation, adisplacement field associated with the stack of image slices withrespect to the reference conformation, the displacement field includinga plurality of displacement components corresponding to the plurality offirst positions, and each image slice of the stack corresponding to onedisplacement component of the plurality of displacement components. 36.The method of claim 35, further comprising: adjusting, based on thedisplacement field, spatial basis function representations correspondingto imaging data, wherein the imaging data corresponds to the stack ofimage slices.
 37. The method of claim 35, further comprising: adjusting,based on the displacement field, the stack of image slices.
 38. Themethod of claim 35, wherein the first conformation corresponds to aplurality of first positions of a first couch reflected in the stack ofimage slices, and the reference conformation corresponds to a pluralityof second positions of a second couch reflected in an image sliceaffording a sagittal view.
 39. The method of claim 38, wherein the stackof image slices are acquired by a first device and the image slice isacquired by a second device different from the first device.
 40. Amethod implemented on a computing device having at least one processorand at least one computer-readable storage medium, the methodcomprising: obtaining a first image slice in a first view relating to asubject or a region of interest (ROI) of the subject and a firstconformation, the first image slice corresponding to a stack of secondimage slices in a second view; and determining an intersection between areference conformation and the first conformation; determining, based onthe intersection between the reference conformation and the firstconformation, the first conformation, and the reference conformation, adisplacement field associated with the first image slice with respect tothe reference conformation, the displacement field including a pluralityof displacement components, and each second image slice of the stackcorresponding to one displacement component of the plurality ofdisplacement components.